Methods

A randomised pilot study including two different interventions and usual care provided to "pregnant teens" recruited through local prenatal clinics and public schools in Pittsburgh, USA. The hypothesis was that an intervention including peer support would be more effective than the intervention alone. The aim was to develop an effective intervention which could be implemented by clinics and schools.
No details of randomisation or whether usual care providers were blinded to allocation.
of bias.

Participants

Inclusion criteria were:
12 to 20 years of age; 4 to 28 weeks gestation; reported smoking at least 1 cigarette a day; single; no previous live birth; able to read and write English.
Exclusion criteria: pregnancy complications preventing attendance at group sessions or participation in a home study program.
84 women recruited (not known how many were eligible or approached), 53 African‐American heritage, 31 European‐American heritage.
29 randomised to UC, 29 to TFS and 26 to TFSB.
46/84 had outcome data post‐intervention. Mean cigarettes/day at first visit: UC = 6.44; TFS = 5.87; TFSB = 6.81.

Interventions

Usual Care (UC) 30 minutes individual educational session with project nurse including information about the risks of smoking to the mother and the fetus + brochures on smoking and pregnancy.
Teen Fresh Start (TFS): cognitive behavioural group model designed specifically for adolescents: 8 modules to heighten awareness and attention to smoking messages; build and enhance smoking cessation skills; teach skills for maintenance of smoking control; includes experiential learning and round robin discussion. TFS was modified to include additional information on smoking and the fetus, body image changes and overall health. The intervention also included social activities, immediate rewards and adult modelling.
Teen Fresh Start + peer support (TFSB) utilised all the components of TFS plus one‐to‐one support through a non‐smoking peer (buddy) chosen by the young woman. Buddies were asked to attend all 8 sessions and to be available at other times for reinforcement of techniques learned and encouragement for continued cessation. High intensity intervention.

Outcomes

Smoking cessation at 4‐6 weeks post baseline, validated by exhaled CO.
Only 46/84 had outcome data (high attrition rate = 45%), UC = 12 (41%), TFS = 13 (46%), TFSB = 13 (50%).
Modified Fagerstrom Tolerance Questionnaire for adolescents to assess nicotine dependence.

Notes

TFS and UC outcomes were combined in this preliminary paper.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

Unclear risk

B ‐ Unclear

Methods

Cluster‐randomised trial measuring (i) the short‐term effects of routine prenatal care provider (midwife) smoking cessation counselling and provision of smoking cessation materials. All midwives in a province were allocated to either intervention or control care. Only 24.2% of chairs of midwifery agreed to approach midwives in their region to participate. The first 40 practices (118 midwives) were selected, from 4 provinces, which were then matched (by location and level of urbanisation) into 2 pairs. (ii)measuring the longer‐term effects.

Participants

Women using public health services, who smoke more than 1 cigarette per day, literate in Dutch, and gravidity less than or equal to 4. 80% eligible population approached. Participation rate 72% (n = 318). Mean cigarettes per day at intake I = 9.1, C = 7.7. Mean gest at intake I = 12.4, C = 13.5. (ii) included women from trial (i) and spontaneous quitters; n = 253 (I) and 303 (C); 80% approached. 72% participation.

Interventions

Control group received routine smoking cessation counselling + a folder about smoking cessation in pregnancy, (Both trials i and ii)
Intervention group received routine care + a minimum of counselling sessions from their midwife, who received a 3 hour training session on smoking cessation counselling and a booklet); a video; self help guide; partner booklet; midwife booklet and post‐delivery booklet. Information was based on the stages of change model.

Outcomes

Self reported quit attempts at 6 weeks postpartum, with urine cotinine biochemical validation in a small proportion of participants (n = 14).
Self reported partner smoking status. Attrition 12.8%, not different in I and C arms, detailed process evaluation, including views of participants and midwives
Attrition rate 12.8%, with NS difference in attrition between experimental and control groups. (ii) Self‐reported quit attempts at 6 weeks and 6 months postpartum; attrition 9.1% (I), 7.9% (C)
Detailed assessment of participant and midwifery views of interventions, including an analysis of psychosocial motives which are thought to be associated with implementation.

Notes

inconsistent information on gravidity criteria. Good process evaluation documented poor implementation in some aspects. A separate detailed paper published on process evaluation issues. (ii) Only 16.7% of women received the post‐delivery booklet. No validation of longer‐term self‐reported smoking.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

Unclear risk

D ‐ Not used

Methods

A randomised pilot study of the effect of medical advice on smoking cessation in pregnancy, in two public antenatal clinics in Bolton and District General Hospital, England. No sample size or randomisation details.

Participants

Women smokers or ex‐smokers, at their first antenatal visit, less than 20 weeks gestation. 110 women, mostly working‐class, mostly long‐term and heavy smokers. I n = 63 C: n = 47.

Interventions

Control group received usual care, which was advice at the discretion of the doctor.
Intervention group received counselling from a senior medical student which involved discussion of the disadvantages of smoking during pregnancy: risk to the fetus; long‐term risks of physical and intellectual impairment and possible reasons for this; possible effects on the mother's own health; costs of smoking; special dangers of smoking in late pregnancy; various ways to help someone to stop smoking. Given strong encouragement to quit and to make a commitment to do so. If this was not agreed then reduction to less than 5 cigarettes a day.
Half the intervention group were given a diary to record each cigarette smoked and a gift of a free smoking diary. No theoretical basis of intervention specified. Intervention intensity = 3.

Outcomes

Smoking cessation assessed by self report in a home interview 11 weeks after baseline visit. No biochemical validation of smoking status.

Notes

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

Unclear risk

B ‐ Unclear

Methods

Randomised trial of effectiveness of use of exhaled carbon monoxide feedback for promoting smoking cessation in pregnancy, in Guildford County, North Carolina. Trial over 6 months in 1981. Allocation by a computer‐generated random number table to experimental or control group. No randomisation details or sample size justification.

Participants

Women currently or recently smoking, attending public clinics. No exclusion criteria details or characteristics of participants in each group. 47% were current smokers, 43% had completed high school education, 56% were black, 80% classified as having no pregnancy risks other than smoking. 38% in the first trimester and 46% in the second trimester of pregnancy.

Interventions

Experimental group provided breath specimen in which carbon monoxide was measured, with feedback of the result, and a 135 word script describing the relationship between CO and cigarette smoking + harmful effects of smoking during pregnancy, by health educator.
Women in the control group were read the script only.
Intervention carried out by regular health educators.

Outcomes

Smoking cessation 6 weeks after intervention confirmed by subsequent CO <= 9 ppm in breath specimen. Outcome measurement for 170/226 women. Attrition rate 24.8%, and allocation not reported.

Notes

Not clear whether this was a group intervention ‐ in which case there was no adjustment for clustering.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

Unclear risk

B ‐ Unclear

Methods

Randomised trial of psychosocial support in pregnancy in 4 hospitals in Latin America (Argentina, Brazil, Cuba, Mexico). January 1989 ‐ March 1991.
Randomisation in balanced blocks of 20, prepared centrally, provided in sealed, opaque envelopes opened after the baseline interview had been completed. Providers unaware of the allocation of women to either arm of the trial.

Participants

High‐risk women whose antenatal care began at 15 ‐ 22 weeks gestation, singleton pregnancy, 1 or more of the following: prior LBW infant; preterm birth; perinatal/infant death; < 18 years; body weight <= 50 kg; height <= 150 cm; low family income (local definitions applied); < 3 years school; crowded household (4 or more persons/bedroom); smoking; not living with husband or partner. 2235 women recruited 1115 to intervention 1120 to control.
Exclusions: heart or renal failure; diastolic BP > 100 mmHg; history of cervical cerclage; Rh negative; mental disease or any chronic disease that might interfere with pregnancy.

Interventions

Control group received routine antenatal care. High intensity intervention involving flexible use of a standardised manual, based on site‐specific ethnographic studies of needs, fears, expectations, social support networks, including detailed descriptions of situations likely to occur during home visits. 4 to 6 home visits of 1 to 2 hours with emphasis on psychosocial support, education on health habits including better nutrition, reducing smoking alcohol and other drugs, reducing their physical workload, recognition of alarm signs and symptoms, improved access to hospital facilities, reinforcement of health service utilization. Additional components were a poster, a booklet, hot line to project office, guided tour of hospital, encouragement of family support and participation. Intervention was provided by specially trained female social workers or obstetric nurses with previous experience of childbirth.

Outcomes

Self reported smoking cessation, no biochemical validation. Multiple perinatal and maternal health outcome data were collected. As there are many paths other than smoking reduction/cessation by which these outcomes might have been modified by the intervention, only smoking cessation has been abstracted in this review.

Notes

Sample size was planned for the primary trial objective.
Process evaluation showing good implementation is reported.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

Low risk

A ‐ Adequate

Methods

Trial of telephone support for improving outcomes in late pregnancy, in the outpatient department of a large maternity hospital in New Zealand, or its associated GP practices, or self‐referral, from March to December 1993. Computer‐generated random assignment to control or intervention in balanced blocks of 50. Caregiver blinded to allocation. No sample size justification. No sample size justification.

Participants

Women with telephone access, who were either single or with an unemployed partner, were recruited before 20 weeks gestation. The eligible population was 221 women of whom 131 took part (103 OPD, 22 from GPs, 6 self‐referred). 49 were never located, 23 were not interested, 10 refused after explanation, 8 moved away, did not speak English or had a miscarriage.
Over 50% of women smoked at recruitment.

Interventions

Introductory letter, phone call, full discussion of "Healthy Mothers/Healthy Babies".
Controls: package of publicly available educational material on healthy behaviours during pregnancy.
High intensity intervention: package + weekly telephone call from trained volunteer with the aim of providing minimal support until 12 weeks after birth; aim "to be a friend and a good listener"; to ask about symptoms; signs; alcohol; drugs; smoking and meals in every call; to encourage attendance at antenatal clinic appointments and to ask about "feeling stressed".
Intervention provided by 19 female volunteers, trained for the project with a "case load" of 2 to 6 women each.

Outcomes

Both perinatal and maternal health outcomes were assessed but as there were other intervention components which might have influenced these outcomes only smoking cessation data were abstracted for this review. No biochemical validation of smoking status. 9 women (of 131) were lost to follow up by late pregnancy, counted as still smoking. Attrition = 7%.

Notes

No process evaluation is reported.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

Unclear risk

B ‐ Unclear

Methods

Trial of CO assessment and brief directive feedback, in a large US municipal hospital antenatal clinic, over an 18 month study period. No description of randomisation. Caregivers blinded to allocation.

Participants

All attending women screened for smoking by questionnaire + CO breath measurement (>= 9 ppm). Pregnant women, currently smoking, at any stage of gestation. Over 50% were current smokers; 40% of women were Black.
Exclusion criteria were very young age (not specified) or "complications" (not specified).

Interventions

Control group (usual care): clinic nurse provided health education, including smoking.
Intervention: usual care + personal letter from the Chief (physician) of the prenatal clinic within 3 days of the visit, mentioning the CO test, discussing the risks of smoking to herself and the fetus and urging her to stop + American Cancer Society pamphlet ("Why start life under a cloud?") about the negative effects of smoking and simple guidelines for self‐directed smoking cessation.

Outcomes

CO measurements (biochemical validation) and smoking data were collected at all subsequent visits.

Notes

Simple intervention so no process evaluation.
Clinic‐wide implementation so no consent sought.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

Unclear risk

B ‐ Unclear

Methods

Trial of provision of videotaped vignettes for promoting smoking cessation and relapse prevention in a community‐based university setting, Texas, US. No details of randomisation, caregiver blinded.

Participants

Volunteers who were willing to quit within two weeks, were recruited through local media, such as newspaper, radio, subscriber letters, community business flyers, waiting room posters. Exclusion criteria: women smoking < 3 cigarettes per day; < 18 years; > 30 weeks pregnant; do not have a working VCR (approximately 12% Americans); not depressed. Participants n = 82. Mean cigarettes/day at first visit I = 17.3, C = 14.5. No significant difference in socioeconomic variables between groups.

Interventions

The control group received a quit calendar and tip guide.
Intervention group were also mailed a video with 6 x 25 ‐ 30 minutes vignettes covering a range of topics and strategies from initial quitting to relapse prevention.

Outcomes

Self reported smoking abstinence obtained within 2‐3 days of quit date, 4‐5 weeks after the quit date and one month postpartum. Biochemically validated with salivary cotinine.
Baseline CES‐D depression scale.
Participant evaluation of intervention materials.
Attrition rate 39%.

Notes

Authors say women in this study tend to be heavier smokers than described in previous studies.
Process evaluation showed only 53% of the intervention group viewed 1 ‐ 3 of the 6 videos. 47% did not view them.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

Unclear risk

B ‐ Unclear

Methods

Trial of "Significant Other Supporter" (SOS) program, of bolstered social support and direct financial rewards, for low income high‐risk women in 4 Oregon WIC program sites, US. Conducted between June 1996‐June 1997. No randomisation details. Quality score = moderate‐risk of bias.

Participants

Women smoking (even a puff in the last 7 days); less than 28 weeks gestation; over 15 years of age; literate in English. Participation rate 71%. Mean salivary cotinine at baseline: I: 45.4 (n = 112);
C: 45.7 (n = 108).

Interventions

Control group received verbal and written information on the importance of smoking cessation, a pregnancy specific smoking cessation self help kit, and were telephoned monthly for self reports on their smoking status.
The intervention group received as for the control group + were asked to designate a social supporter (preferably a female non‐smoker), and were advised both she and her supporter would receive an incentive: participant = $50 voucher/month biochemically confirmed as quit. Supporter = $50 voucher in first month and at 2 months postpartum, and $25 voucher for other months. High intensity.

Outcomes

Smoking cessation biochemically validated with salivary cotinine at 34 weeks gestation and 2 months postpartum. Attrition rate I = 32%; C = 51.5%.

Notes

Data in outcome tables is inconsistent.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

Unclear risk

B ‐ Unclear

Methods

Randomised trial of advice to stop smoking in pregnancy, provided by a (public health) doctor, reinforced by the woman's own GP and other providers involved in shared antenatal care, in 3 UK maternity units. Randomisation details unclear. Caregivers not blinded (asked to reinforce information). Quality score = high‐risk of bias.

Participants

Pregnant women < 35; currently smoking >= 5 cigarettes/day and had been smoking >= 1/day at the onset of pregnancy; < 30 weeks gestation at first visit; no prior perinatal death; not seeking, nor sought termination. Other exclusions: not pregnant; refused consent; miscarriage or termination of pregnancy; moved to another care provider; twin pregnancy or birth before 28 weeks.

Interventions

Control group received ANC usually provided by the hospital, including any anti‐smoking advice which may have been given routinely. Intervention: individualised medical advice
(i) tell the woman the facts about smoking in pregnancy;
(ii) encourage questions about these facts;
(iii) once the woman has agreed to try, discuss how she may best give up;
(iv) follow up the advice at all later contacts. Medical records labelled asking other staff to reinforce advice.

Outcomes

Self reported smoking in cigarettes/day at four stages of pregnancy; mean birthweight; low birthweight; preterm birth (< 36 weeks); perinatal deaths. No data on smoking cessation.
No biochemical validation of smoking status.

Notes

Details of the intervention are in Donovan et al 1975 [see Donovan 1977].
Good discussion of common problems identified when advising women to stop and on the contextual factors which encourage the continuation of smoking.
Process evaluation of the reinforcement of advice showed little difference between the groups in recall of advice being given.
Major inconsistency in smoking reports pre and post birth is a problem in this trial.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

Unclear risk

B ‐ Unclear

Methods

Trial of midwifery counselling around the "stages of change" model", in a large UK maternity. No details of randomisation and caregivers aware of allocation. Quality score = high‐risk of bias.

Participants

100 women; pregnant and booked for maternity care; < 18 weeks gestation; currently smoking 1 or more cigarettes/day. 13 midwives selected for the intervention group and 13 for the control group.

Interventions

Intervention midwives were trained to assess the stages of change and provide a behavioural intervention, using the Health Education Authority material "Helping pregnant smokers quit: training for health professionals", 1994.

Outcomes

Smoking cessation; cigarettes/day; "stage of change" at 11 to 18 weeks vs 37 weeks. No biochemical validation of smoking status.

Notes

3700 births/year at the hospital, all women who smoked were eligible to take part so it is not clear why only 100 took part (described as "all 100").
No process evaluation reported.
UK.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

Unclear risk

B ‐ Unclear

Methods

Prospective randomised controlled trial in 5 health centres of the same HMO in Los Angeles, 1985 ‐ 87. Educator turned over a pre‐assigned card after a brief smoking related interview to determine allocation.

Participants

English‐speaking women < 18 weeks gestation; still smoking >= 7 cigarettes a week (n = 323, 165 + 158, with losses due to termination (7 + 11); miscarriage (12 + 13); disenrollment or transfer to another HMO (20 + 18); leaving 126 + 116.

Interventions

Control group: 2 page pamphlet on hazards of smoking and on the need to quit; 2 minutes discussion with a health educator (within a 45 minutes individual conference); advised of free 5 session smoking cessation program available through the HMO. Coverage in antenatal classes remained unchanged.
Intervention group: as for the control group + first of series of 8 self‐help booklets aimed to increase motivation for quitting; teach behavioural strategies for cessation and relapse prevention; 3 minutes introduction to these by health educator; asked to make a commitment to read the first one and list reasons for not smoking; others mailed weekly. Booklets were pregnancy‐specific, multi‐ethnic, and at a 9th Grade reading level.

Outcomes

Smoking cessation validated with urine cotinine; birthweight; low birthweight; preterm birth (< 37 weeks); stillbirths. Attrition I = 51%, C = 49%.

Notes

Process evaluation showed good implementation.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

High risk

C ‐ Inadequate

Methods

Ershoff 1989 trial data of relapse prevention in the women who had spontaneously quit smoking in early pregnancy.

Participants

The pre‐pregnancy smokers who had quit spontaneously before the first antenatal contact: 110+ 108, with losses due to termination (5); miscarriage (17) and transfer to alternative prenatal care (25) leaving 87 + 84.

Interventions

See Ershoff 1989 except that the intervention group received the first 4 booklets at the first interview with booklets 5 to 8 mailed weekly thereafter; control group were congratulated on quitting and given a tip sheet on "staying quit".

Outcomes

Smoking data validated with urine cotinine only collected, no perinatal data.

Notes

Detailed process evaluation and analysis of factors promoting or inhibiting cessation and maintenance of non‐smoking.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

High risk

C ‐ Inadequate

Methods

Trial of three alternative methods of smoking cessation interventions, in a large group model managed care organization in California, US. No details of randomisation. Caregivers blinded to allocation.

Participants

Smokers were identified at first visit as women who self report "smoking now", "smoke but have cut down since pregnancy", or "smoke from time to time". Researchers attempted to phone all women over 18 years and less than 26 weeks gestation (n = 931). 150 could not be contacted and 90 refused to be interviewed. 233 were excluded as they did not speak English (n = 44), smoked less than 7 cigarettes per week pre‐pregnancy (n = 114) or experienced miscarriage (n = 34). 380/458 women (82%) agreed to participate. 60% white, approximately 50% college educated, with a mean age of 29.4. Mean cigarette/day at first visit = 6.6.

Interventions

3 interventions, based on stages of change model.
Group 1: received a self‐help booklet "living smoke‐free".
Group 2: (n = 120): received the same self help booklet and had access to a computerised interactive telephone support system, which provided customised messages from a voice model.
Group 3: (n = 101):
received the same self help booklet and 4‐6 x 10‐15 minute telephone counselling sessions by nurse educators trained in motivational interviewing. A personalised postcard sent to reinforce verbal communication.

Outcomes

Smoking cessation in the third trimester "not even a puff in the last 7 days", biochemically validated with urine cotinine. Baseline mental health index and Cohen's perceived stress scale.
Number of quit attempts and movement in stages of change.

Notes

Data from group one and group three only compared in outcome tables. Good process evaluation of each of the methods.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

Unclear risk

B ‐ Unclear

Methods

Randomised trial of a smoking cessation and relapse prevention intervention in an urban, prenatal clinic in Baltimore, US. Nov 1996 ‐ June 1997. No details of randomisation and caregivers not blinded to allocation.

Participants

Pregnant women currently smoking (even 1 puff in the past 7 days); < 28 weeks gestation; African‐American or white; 85% of whom were on medical assistance, attending the Outpatient Department at Johns Hopkins. No other exclusions specified. 2319 women assessed, 32% currently smoking by above definition, ‐1585 non‐smokers, ‐72 (gestation, ethnicity, not interviewed at their first visit or changing to another care provider) leaving 662 eligible of whom 510 agreed to take part. 25 quit prior to first visit, 18 did not wish to quit, leaving 467 (232 + 235) reduced by withdrawals, miscarriage, termination and change of care provider to (193 + 193). Mean cigarettes/day at intake I = 9.7, C = 7.5 (P = 0.01).

Interventions

Control: a brief discussion with a nurse about the risks of smoking; a recommendation to quit and pamphlets from the areas's voluntary agencies.
Intervention: Peer health counsellors recruited from local communities, received 2 sessions training from PIs who explained content, rationale and how it was to be provided, then observed in practice by PIs with feedback to her.
(i) A Pregnant Woman's Guide to Quit Smoking (RA Windsor), 6th Grade level.
(ii) 15 minutes 1:1 counselling session with peer health counsellor on how to use the Guide, showing how it is organised to be used daily, and discussing women's thoughts and concerns about quitting, targeting cessation or relapse prevention, as appropriate.
(iii) Educational materials for cessation support persons included with the Guide.
(iv) Reinforcement at each clinic visit from doctors and nurses, written prescription to stop smoking provided directly from doctor to woman; 2 letters of encouragement (from the doctor and the counsellor) mailed to the woman 1‐2 weeks after her first visit.

Outcomes

Smoking cessation in third trimester, validated by salivary cotinine.
Attrition I = 35.2%, C = 35.3%.

Notes

Guide developed through needs assessment with pregnant women, constructs from the PRECEDE/PROCEED diagnosis and social learning theory, tested with focus groups, additional section on relapse prevention, and on passive smoking postpartum.
Process evaluation showing good implementation.
Discussion by authors of the extremely disadvantaged population in inner city, with major neighbourhood level factors of unemployment, poverty, drug use, violence and crime.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

Unclear risk

B ‐ Unclear

Methods

Randomised trial in physicians offices and clinic sites within Maine, 1984‐7, of providing feedback on cotinine measured in maternal serum screening programme (for the identification of open neural tube defects) as part of an smoking cessation intervention. Random allocation through computer‐generated number on maternal serum screening request form. Caregiver not blinded.

Participants

Pregnant women with a singleton live pregnancy; having maternal serum AFP screening at 15‐20 weeks gestation; who smoked >= 10 cigarettes a day. 25,628 screened, 97% answered question on smoking, about 3,000 met smoking criteria (17%). 1423 intervention and 1425 control with 41 + 39 lost to follow up.

Interventions

Control: standard medical care not otherwise specified.
Intervention: report on cotinine generated for her physician with interpretation relating smoking level to birthweight. Physician explained this to the woman and gave her also a copy of the report and a pregnancy‐specific booklet about how to quit, using the cotinine information also + repeat measure 1 month later, 2 copies to physician, comparison of 1st and 2nd cotinine, report commenting on the change and its interpretation.

Outcomes

No smoking cessation data. Smoking data limited to comparability at first assessment and serum cotinine levels; mean birthweight; low and very low birthweight; preterm birth (< 37 weeks); fetal deaths; neonatal deaths; postneonatal deaths. 695/1343 women provided repeat serum cotinine for comparison.

Notes

Physician consent only sought.
Process evaluation showed less than good implementation with differential impact on perinatal outcome by completeness with second blood samples taken for cotinine measurement.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

High risk

C ‐ Inadequate

Methods

Cluster randomised trial of a brief midwife‐delivered smoking cessation intervention in 9 hospital and community trusts in the UK. 290 midwives randomised to provide intervention or control care. Sample size justification.

Participants

Women recruited at first visit (approximately 12 weeks gestation) and considered eligible if they reported current smoking or having stopped within the last 3 months (n = 1287). 189 current smokers not motivated to stop, therefore received no intervention.

Interventions

Control group midwives received 1 hour of training to discuss the study and were asked to provide usual care and any usual pamphlets. Intervention midwives received 2 hours training which included using the CO monitor and providing "stage of change" based advice, CO assessments. Intervention group also received written advice and motivational materials for current and recent smokers, including designating a "quit date", a "quiz" and the offer of "buddying" to another pregnant smoker for support.

Outcomes

Smoking cessation biochemically validated with exhaled CO in the early postnatal period and at 6 months postpartum.
Birthweight for smokers and ex‐smokers recorded.
Participants views of interventions reviewed.
Attrition rate 7%.

Notes

Data not adjusted for clustering, so they were not included in outcome tables. Good process evaluation showed poor implementation in some areas, with only 61% of midwives actually recruiting any women for the study. Financial incentives paid to service to improve recruitment. Discussion of barriers includes 65% of midwives reporting the intervention could not be undertaken in the time they had available.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

High risk

C ‐ Inadequate

Methods

Trial of medical smoking cessation counselling and peer support, in a teaching hospital (academic) clinic in North Carolina 1991‐1993. Randomised by computer‐generated random number table and charts "flagged" to identify those in the intervention group.

Participants

All women receiving prenatal care at the University of North Carolina residents clinic were surveyed: 842/846 completed survey; 793/846 provided a carbon monoxide breath sample; 2 were excluded as > 36 weeks gestation; 1 for psychiatric diagnosis; leaving 266 eligible smokers (smoked at least once in the prior week) of whom 12 refused, 4 were missed, 2 were not pregnant and 1 was a private patient; 247 recruited, losses were 40 (‐4 miscarriage first trimester, ‐3 miscarriage second trimester, ‐ 3 terminations, ‐15 moved to alternative care , ‐12 lost to follow up) leaving 107 intervention and 100 control.

Interventions

All 1‐4 year residents given didactic and role play training for smoking cessation counselling, including self‐assessment of current techniques and skills, which they were asked to continue with for the control group.
Control group: standard care; residents reminded not to alter amount or time of this; help was provided if woman sought it and prenatal classes included discussion of substance abuse including cigarettes.
Intervention: (i) residents provided counselling at each visit, and a brief script aimed at setting a quit date or negotiated an alternative assignment such as a smoking diary at every contact;
(ii) given Windsor's self directed 7 day smoking cessation guide;
(iii) quit date patients given written prescription to quit, letter of support from doctor, contacted by volunteer smoking cessation counsellor to review the quit plan and encourage follow‐through
charts flagged, prompts with flow sheet, most recent CO and self report included for care provider;
(iv) successful quitters sent an encouraging postcard each week.

Outcomes

Smoking cessation biochemically validated by exhaled CO at each visit. Attrition rate 16%.

Notes

Concerns about residents having to treat similar/consecutive patients differently, and self‐help manuals accidentally given to some controls.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

High risk

C ‐ Inadequate

Methods

Trial of multimodel intervention to promote smoking cessation in pregnancy in a large midwifery centre in the Netherlands, 1996 ‐ 1998. Quasi‐randomised, allocation of even/uneven birth dates to designated clinic days. Usual caregivers provided intervention, so not blinded to allocation. Sample size justification.

Participants

Pregnant women attending first antenatal visit (approximately 16 weeks gestation) who identified as "daily smokers" were invited (n = 905). Exclusion criteria: inability to speak Danish; age > 18 years; gestation > 22 weeks; verified psychiatric disease, and alcohol or drug abuse. Participation rate 77% (n = 696). I = 348, C = 347. 87 in the intervention group accepted intensive smoking program (81 group & 6 individual). 75 opted to use NRT. Withdrawals = 48 (miscarriage, moving and premature birth) excluded from the smoking cessation outcomes. Mean cigarettes/day = 11 in both groups. Significant difference in partner smoking I = 67%, C = 77% (p = 0.03).

Interventions

Control group received standard smoking cessation counselling from their midwife about risk of smoking and general advice on cessation or reduction, within the standard 30 minute booking consultation.
The intervention group all received an extended first antenatal visit of 40 minutes, which included a dialogue, and written information on hazards of smoking in pregnancy and for newborns. This information was reinforced in the following 5‐6 antenatal visits, within the normal 20 minute visit.
Women were invited to join the intensive smoking program, based on cognitive behaviour modification program, with 9 group (90 minutes) or individual sessions (15‐30 minutes), conducted over 14 weeks, by specifically trained midwives. Exhaled CO monoxide levels taken at each visit, the first 3 weeks prepared women for quitting, with 6 attendance to maintain cessation and provide an NRT regime tailored to Fagerstrom nicotine dependence assessments.

Outcomes

Self reported smoking cessation at 37 weeks gestation, biochemically validated in 51% participants.
Mean birthweight; low birthweight (< 2500 g); preterm births (< 37 weeks).

Notes

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

High risk

C ‐ Inadequate

Methods

Quasi‐randomised (allocation by birth date) trial of smoking cessation intervention ‐ based on RA Windsor self help manual ‐ in 13/14 public health maternity clinics in Gothenburg, Sweden 1987‐1988.

Participants

Women who spoke Swedish, smoking >= 1 cigarette/day, gestational age < 12 weeks at first antenatal visit, (no other exclusion criteria specified), leaving n = 745 of whom 22 had quit by the second antenatal visit. 15% refused to take part (‐75) leaving 417 in the intervention and 231 in the control group.

Interventions

All women were advised to quit by the midwife at the first antenatal clinic; pre‐intervention.
Control: basic information sheet given to women by the doctor with basic facts about smoking and pregnancy + recommendation to quit.
Intervention: self help manual based on Windsor 1985, revised and with new parts added, distributed by the obstetrician at the second antenatal visit.

Outcomes

Smoking cessation data; biochemically validated (blood thiocyanate < 100 ng/ml) at first and second antenatal visit and in late pregnancy, and postpartum; mean birthweight; low birthweight; preterm birth (< 36 weeks).

Notes

Same data published by Svanberg 1992.
No process evaluation.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

High risk

C ‐ Inadequate

Methods

Trial of tailored, scripted "stage‐of‐change" intervention and fact booklet, for infertile and pregnant women, in 3 university teaching hospitals in Ontario, Canada. Randomisation of consenting participants using a computer‐generated, blocked schedule, administered through numbered opaque envelopes. Caregivers not blinded to allocation.

Participants

Pregnant women smoking 3 or more cigarettes per day in the past 6 months. Mean gest at enrolment I = 18.91, C = 20.55. 110 recruited. Mean number of cigarettes/day I = 13.43, C = 12.

Interventions

Control group completed a questionnaire and self identified current smoking "stage of change" and received standard information about the negative effects of smoking in pregnancy, reinforced with whatever literature was available and CO measurements. The intervention group received the same as the control group + (i) scripted advice prompted by sets of cards, which are tailored to each stage; (ii) stage specific information booklets; (iii) referral for more in depth counselling.

Outcomes

Self reported smoking levels, validated by exhaled CO, and movement in the stages of change measured at enrolment, 6 and 12 months.
Number of quit attempts; triggers for resuming smoking.

Notes

Data from both infertile and pregnant women combined, so not included in tables.
Process evaluation provided and only 5/56 accepted referral to a smoking cessation clinic. Concern selective intervention by the same provider may have influenced "routine" advice to the control group.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

High risk

C ‐ Inadequate

Methods

Canadian double‐blind, placebo controlled trial of nicotine replacement therapy (patches) in pregnancy.

Participants

Women recruited from the Motherisk Program at 12‐24 weeks gestation, smoked > 15 cigarettes/day, and who reported they wanted to quit, but could not do so, in the first trimester.

Interventions

Intervention group received a 12 week NRT patch regimen: 18 hour 15 mg patch for 8 weeks; 10 mg patch for 2 weeks, and 5 mg patch for 2 weeks + counselling with a video presentation at baseline, 1, 4 and 8 weeks.
Control group received as for intervention group, with a placebo patch. Weekly telephone support was given from one investigator to encourage continuation with the program, enquire about adverse effects and to co‐ordinate clinic visits. All women were encouraged to call the investigative team for advice, reassurance and support.

Outcomes

Smoking cessation during second trimester, biochemically validated with serum and salivary cotinine levels.

Notes

Study ceased after only 30 women recruited due to severe withdrawal symptoms in the 30th recruit (allocated to placebo).

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

Low risk

A ‐ Adequate

Methods

Cluster randomised trial of smoking cessation in public prenatal and WIC clinics in Maryland, Colorado and Missouri, USA, 1987‐89. Clinics stratified by size of clinic and also by prior low birthweight programme (Colorado) or % minority clients (Maryland), and randomly assigned to deliver either intervention or continue with standard care.

Participants

5262, 6087 and 4943 pregnant women screened in Colorado, Missouri and Maryland respectively, with nearly 50% of women in each State smoking. Smoking defined as "even a puff within the last 7 days before the women knew she was pregnant" (includes recent quitters). Consent for data collection ranged from 66% to 79%. High proportions were young, < 12 years education, White, unmarried and poor. Mean gest at enrolment = 15.2 ‐ 16.6 weeks. Mean cigarettes/day at enrolment combined for smokers = 12 cigarettes/day.

Interventions

Control: usual care not otherwise specified.
Interventions based on stages of change, but differed by State, locally adapted with some detailed development.
Colorado: 1‐5 minutes counselling; assessing smoking status; quitting tips; supportive statements by nurse‐clinicians; health care providers' Guide; 8 brochures for pregnant smokers; additional one for women postpartum.
Maryland: brief clinic‐based counselling program + self help material focussing on the stages of quitting.
Missouri: "becoming a life‐long smoker" 6 minutes with clinic patient brochures, flip charts; 1 ‐ 2 minutes at WIC clinics training staff, chart documentation and forms.
All included effects of smoking on the fetus; benefits of quitting; quitting techniques; developing social support; preventing relapse and limiting exposure to environmental tobacco smoke. All materials were at 6th Grade reading level.

Outcomes

Smoking cessation biochemically validated with urine cotinine. The necessary adjustment for clustering means that the data cannot be put into the standard table of comparisons. Adjusted data showed no differences in verified quitting, mean birthweight or low birthweight.

Notes

Substantial misclassification of self report as non‐smoking: 28% at enrollment; 35% at 8th month; 49% of self reported quitters at intervention clinics; 32% of self reported quitters at control clinics. Process evaluation suggested less difference between I and C clinics than might have been expected.
Project staff felt that the use of existing staff to deliver the new interventions and to collect data affected the study negatively especially given the time needed to process questionnaires and urine samples. This led to less than full implementation and variable motivation to promote smoking cessation counselling among staff.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

Unclear risk

B ‐ Unclear

Methods

Cluster‐randomised trial of two different interventions, in community midwife clinics in the West Midlands region of the UK. A computerised minimisation programme was used to allocate 72 eligible practices into 3 equal groups from 101 available practices. Caregivers not blinded (implementing intervention). Sample size calculation given, but unable to recruit sufficient numbers. 17 practices added to arm A, 12 to arm B and 0 to arm c to increase recruitment.

Participants

Inclusion criteria were all women seen in routine antenatal appointments who were aged 16 years or over, a current smoker at booking. Women not fluent in English were excluded. Initial target of 1440 participants was reduced to 900 due to slow recruitment (particularly in standard care arm). Eligible smokers approached A = 34%, B = 47%, C = 75%. Refusal rate A = 13.4%, B = 7.2%, C = 22.5%. Mean cigarettes per day at baseline were similar between groups.

Interventions

Control group (A) received standard care. Midwives received a half day training on research protocol, and asked all midwives to give women the Health Education Authority booklet "Thinking about stopping". Group B midwives received two and a half days training on theory of transtheoretical model. Participants received a set of 6 stage based self help manuals "Pro‐Change programme for a healthy pregnancy". The midwife assessed participants stage of change and pointed the woman to the appropriate manual. No more than 15 minutes was spent on the intervention. Group C midwives received the same training as for Group B, and participants received the same self help manual and intervention as group B. Additionally the participants used a computer programme on the occasions, which consisted of questions to stage the woman with auto feedback of what stage they were in and what this meant, and a range of other concepts. It took about 20 minutes for the woman to complete. Printed information of the feedback was sent to the participant within a week of the intervention.

Outcomes

Biochemically validated smoking cessation at 28 ‐ 30 weeks gestation and 10 days post birth. Point prevalence and sustained abstinence of 10 weeks or more were calculated.
Effect of midwife training (attitudes, expectations, confidence, concerns and routine practice) was assessed by pre‐post training questionnaires.
207 women (22.5%) withdrew from the study, 77 due to early end of pregnancy, 38 changed practice, 32 declined further participation and 60 left for other reasons, with similar rates of withdrawal between groups, except for failure to complete the questionnaire and provide a urine sample, with highest compliance in Group C.

Notes

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

High risk

C ‐ Inadequate

Methods

A randomised trial in Newcastle Hospital antenatal clinic (UK) and with other shared antenatal care providers of individual counselling to promote smoking cessation over 3 months in 1982.
Simple randomisation in balanced blocks of 8. Unclear whether caregivers masked.

Participants

All pregnant women currently smoking >= 1 cigarette a day at the time of the first antenatal clinic, and < 28 weeks gestation. 156 contacted, ‐5 > 28 weeks leaving 151, 5 exclusions (not pregnant, guilt over previous stillbirth, and 3 miscarriages), leaving 72 (I) + 73 (C).

Interventions

Control: usual antenatal care + possible exposure to a concurrent television series (6 x 10 minute programme on stopping smoking in pregnancy).
Intervention: (i) 10 minutes anti‐smoking advice from SHO (Resident) based on Health Education Council Booklet "So you want to stop smoking.. for you and your baby", an additional leaflet from the same source, and copies of the booklet for other family members;
(ii) woman's GP sent a letter describing the purpose of the study and a booklet, asked to reinforce the information at usual contacts;
(iii) 2 weeks later a letter of reinforcement was sent to the woman;
(iv) 4 weeks later there was a preplanned home visit to provide anti‐smoking advice with a letter of the same advice sent if the woman was not at home;
(v) possible exposure to the concurrent TV series.

Outcomes

Smoking status and smoking/day assessed 6 weeks later. Not biochemically validated.

Notes

Short interval between intervention and assessment.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

High risk

C ‐ Inadequate

Methods

Trial of anti‐smoking interventions (individual and group) based on the MRFIT trial, carried out in Oregon where 95% of pregnant women attending one of the two hospitals were enrolled in the Kaiser Permanente HMO, 1979‐1980. No details of randomisation or whether caregivers masked to allocation.

Participants

, questionnaire response rate 25%. Pregnant women contacted at first antenatal visit: 3856 asked about smoking; 963 self reported current smokers (25%). 21% of them in receipt of public assistance but only 7% of non‐smokers. Poor participation in the study: 83.6% contacted; refusal rate 37%.

Interventions

Planned intervention: (i) letter of invitation with sae, reminder letter;
(ii) group information meeting on programme for respondents with short information session by physician;
(iii) individual session with trained smoking counsellor;
(iv) 6 x 1.5 hour group sessions, once a week;
(v) subsequent support groups, individual sessions and phone calls.

Outcomes

Smoking cessation by late pregnancy, biochemically validated with cord blood thiocyanate in a subsample, but no misclassification of self reported non‐smoking.

Notes

Very poor response to group sessions so intervention changed over the course of the trial to individual counselling, which also had very low participation overall: 18% active; 25.2% dropped out; 38% did not participate; 18% could not be contacted.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

Unclear risk

B ‐ Unclear

Methods

A randomised trial of relapse prevention among women who had stopped smoking since the beginning of pregnancy, in the public maternity clinics of a large hospital in Birmingham, Alabama 1987‐1989, USA.
No details of randomisation and caregivers not masked.

Participants

Pregnant women recruited at their first prenatal visit reporting as having quit since conception, no exclusions mentioned, n = 115, 9 refused to participate leaving 106 of whom 3 had a miscarriage, 4 moved and 2 had babies for adoption, leaving 54 (I) and 45 (C), Follow up data were available on 80%.

Interventions

Control: nurses' advice to all women not to smoke.
Intervention: 10 minute counselling by health educator using smoking relapse prevention materials on effects of smoking; benefits of maintaining cessation; possible problems; smoking triggers; solutions to smoking cues; strategies for staying quit + contract + flip chart (5th Grade reading material + 'stay quit buddy' encouragement = non‐smoking gifts and pamphlets) + clinic reinforcement by prenatal staff through reminder form in the notes + staff training to confirm abstinence, praise, encourage continuing cessation.

Outcomes

Smoking cessation in late pregnancy, biochemically validated with salivary thiocyanate. Included in relapse prevention outcome tables only.

Notes

Concurrent trial with Windsor 1993.
Process evaluation showed good implementation.
Issues of possible 'contamination' in clinics with individual randomisation discussed.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

Low risk

A ‐ Adequate

Methods

Quasi‐randomised study using alternate allocation within antenatal clinic of a large metropolitan public hospital in Brisbane to assess the effectiveness of a self‐help booklet developed by Windsor (for women of low socioeconomic status ‐ mostly black women ‐ in Alabama), in urban Australian women. This first trial (i) was followed by a second one (ii) with a modified intervention, but no other change to the methods

Participants

All pregnant women attending for a first antenatal clinic, who identified themselves as current smokers, had no current complications of pregnancy and were not planning to have the child adopted, were approached at their first antenatal clinic appointment (n = 244 ‐ 27 who declined = 217).(ii) Participation rate of 91%, 108 women recruited, 8 had a miscarriage or fetal death or discontinued care at the hospital; 2 withdrew from the study and 19 were lost to follow up (LTFU) by 20 weeks. All those LTFU were counted as continuing smokers

Interventions

Control: given the self help booklet and a midwife caution against smoking.
Intervention: as for control + a 15 minutes 1:1 motivational counselling session provided by the midwife, focussing on the booklet (based on cognitive behaviour strategies), a flip chart which demonstrated the effects of smoking on the fetus, being shown how to use the manual, two contracts developed (partner and non‐smoking friend) and these people contacted to sign. Aim was to increase self‐efficacy and create a social support structure for women during her attempts to quit and motivating her to use the booklet. (ii) Booklet modified through focus groups with input from health promotion specialists, medical specialists and GPs, to a glossy format with coverage of additional topics (growth and development of the fetus, enjoyment of certain foods and sex during pregnancy, emotional and physical aspects of pregnancy and stopping smoking. (C): only the midwifery caution against smoking; (I): the midwife provided the booklet without any additional discussion or counselling.

Outcomes

Smoking reduction and cessation assessed at the 20 week visit. Biochemical validation of smoking status in self reported non‐smokers, same for (i) and (ii).

Notes

Process evaluation showed poor response to the booklet.
Focus groups with women from I and C identified problems with the material and made suggestions about changes.
Discussions with staff showed time pressures over counselling component.
Trial stopped and redesigned, see (ii). Second trial (ii) had a positive process evaluation though staff identified a range of barriers to implementing smoking cessation counselling.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

High risk

C ‐ Inadequate

Methods

See Lowe 1998a for setting as this trial followed immediately after the first one. Quasi‐randomised trial with alternate weeks allocated to control and intervention.

Participants

See Lowe 1998a. The participation rate was 91% with 108 women recruited of whom 8 had a miscarriage, or a fetal death or discontinued care at the hospital. Two more withdrew and 19 were lost to follow up by 20 weeks. All those lost to follow up were counted as continuing smokers.

Interventions

Booklet modified from the one used in Lowe 1998a, through focus group discussions with input from health promotion specialists, medical specialists and GPs to a glossy format with coverage of other topics (growth and development of the fetus, enjoyment of certain foods and sex during pregnancy, emotional and physical aspects of pregnancy and stopping smoking).
Control group: only the midwifery caution against smoking.
Intervention: the midwife provided the booklet without any additional discussion or counselling.

Outcomes

Smoking behaviour and smoking cessation at 20 weeks, biochemically validated.

Notes

Process evaluation of materials was positive, though staff identified a range of barriers to implementing smoking cessation counselling.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

Unclear risk

D ‐ Not used

Methods

Quasi‐randomised trial with alternation of 4 week blocks to intervention or control in a large English city maternity hospital to identify effects on fetal size at birth mediated by an anti‐smoking intervention, 1981‐1982.
MacArthur 2001 reported follow up when the children were nine

Participants

Pregnant women smoking at booking: 29% had been pre‐pregnancy smokers, 23% were smoking at booking. 1008/1156 women identified as smokers interviewed, 48 lost (early discharge, infection/isolation, changed surname); Exclusions were multiple births (6 (I) + 8 (C); records not linked to hospital data 8 (I) + 4 (C)) leaving 493 (I) and 489 (C). Mean cigarettes/day at booking I = 14.4, C = 13.7.

Interventions

Intervention: advice to stop smoking + information or discussion of the effects of smoking on the fetus offered by the obstetrician at the first antenatal (booking) visit, supported by giving her a leaflet to be shared with the partner, family and friends. If leaflet not given by obstetrician, the midwife was asked to give it to the woman and advise her to stop smoking.
Control: routine advice, not specified further.

Outcomes

Smoking cessation and reduction ‐ biochemical validation commenced, but abandoned when it became clear it did not distinguish levels of smoking. Birthweight, length and head circumference;
Height, weight, IQ and neuromaturity at 9.4 years. Experimental results only discussed in this review (data according to group allocation).
Report includes observational data (according to smoking behaviour) smoking status not biochemically validated.

Notes

Consent not sought from individual women, implementation of the trial across all clinics routinely. Process evaluation shows poor implementation, with only 10% receiving "full intervention".
No details of the content of the leaflet.
Follow‐up data not sufficient for tabulation.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

High risk

C ‐ Inadequate

Methods

Trial of effects of peer counselling on smoking cessation and reduction in a large urban clinic. Hartford Hospital, US, Jan 1998‐Feb 2000. Computer‐generated random allocation, with usual care providers masked to allocation.

Participants

Low income, uninsured women, who smoke "at least one cigarette per day before pregnancy, less than 20 weeks gestation, literate in English or Spanish, and intending to carry to term. High smoking prevalence in pregnancy (29%). Recruited n = 142 (I = 67, C = 75). Mean cigarettes/day at baseline significantly higher in intervention group. I = 13.3, C = 11.2.

Interventions

The control group received routine care, which included the program of "Ask, Advise, Arrange and Assist", based on cognitive behaviour, described by Windsor et al, 2000. The intervention received as for the control group + peer counselling from lay community health outreach workers (telephone or home visits). Peer counsellors received 2 x 3 hours of training.

Outcomes

Smoking cessation and reduction at 36 weeks gestation, biochemically validated with urine cotinine and exhaled CO.
Nicotine addiction assessments (Fagerstrom Tolerance Questionnaire), and breastfeeding at 6 months postpartum.
Infant birth weight correlated with cigarettes/day in late pregnancy. Attrition rate I = 43%, C = 36%.

Notes

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

High risk

C ‐ Inadequate

Methods

Cluster randomised trial of a smoking cessation program in 10 public clinics in Chicago, US, 1994‐6. Randomisation to study group within matched pairs of clinics.

Participants

Clinics matched on size, type, location, and racial mix of clientele. Smokers in intervention group more likely to be African‐American. Participation rate I = 76% (n = 1025), C = 86% (n = 784). Mean cigarettes/day at intake.

Interventions

Control group received smoking cessation advice and available brochures, dependant on the clinician. The intervention group received brief advice to quit (from a variety of clinicians), a written agreement on a quit date, a take home motivational self‐help booklet "Its Time", a reminder letter, and a 15 minute telephone motivational interview. High intensity intervention based on stages of change theory and Millers brief motivational interviewing approach.

Outcomes

Self reported smoking cessation, not biochemically validated. Movement in stages of change. Attrition rate I = 38%, C = 41%.

Notes

Data not included in outcome tables due to inconsistent data reporting (baseline and control groups combined) and data not adjusted for clustering.
Good process analysis provides outcomes by exposure to intervention.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

High risk

C ‐ Inadequate

Methods

Trial comparing three smoking cessation interventions in WIC clinics in Grand Rapids, Michigan, USA, 1985‐86. Not details of randomisation or whether caregivers masked to allocation.

Participants

Women currently smoking (>= 1 cigarette/day) comprised 271/641 attending the clinics (42%), 219 agreed to take part, data on 186. Losses to follow up were that a quarter refused, and the rest either moved, changed their source of antenatal care or had a miscarriage (no details of numbers). Mean cigarettes/day prior to pregnancy I = 19.9, C = 20.3.

Interventions

Control: printed information about the risks of smoking in pregnancy.
Intervention (a) risk information: 10 minute discussion with a health educator using a flip chart and a brochure but with no behaviour change counselling or self‐help manual.
Intervention (b) multi‐component: 20 minute 1:1 counselling including risk information ("Because I Love My Baby" Am Lung Assoc + flip chart + brochure to take away), and behavioural change manual adapted from RA Windsor and the Am Lung Assoc "Freedom from Smoking" focussing on contracting and self monitoring (cognitive behaviour therapy).

Outcomes

Smoking cessation in late pregnancy and postpartum, biochemically validated with salivary thiocyanate in approximately a third of participants, but no adjustment for misclassification.

Notes

No process evaluation.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

Unclear risk

B ‐ Unclear

Methods

Randomised trial of relapse prevention at the Group Health Cooperative of Puget Sound (Seattle, USA) (HMO), and Park‐Nicollet of Minnesota (USA), a multispecialty group practice. No details of randomisation. Caregivers masked to allocation.

Participants

Women booked for a first prenatal visit were offered, by letter, study participation and unless they opted out were given a baseline telephone interview. Women who had completed the baseline survey, were < 20 weeks of pregnancy, were currently smoking or had smoked in the 30 days before pregnancy but had quit at the time of the baseline survey.
They were stratified by baseline smoking status.
9152 approached, 714 ineligible because of miscarriage, pregnancy termination, inability to speak English; 697 refused; 262 could not be reaches by telephone after repeated attempts. 7479 completed survey. 1007 were randomised: 88 miscarried and were excluded; 22 were sent wrong intervention material; 897 participated (457 from Seattle, 440 from Minnesota). Mean cigarettes/day 4.8 in intervention and control groups.

Interventions

There were 3 stage of change based interventions, all delivered by mail or telephone without involving prenatal care providers.
(1) Self help booklet "Stop now for your baby"; 5th grade reading level; health effects of smoking during pregnancy; specific suggestions for quitting (setting date, enlisting support). For recent quitters: stress reduction techniques; suggestions for handling high‐risk situations; pregnancy‐appropriate behavioural alternatives to smoking.
2. & 3. High intensity interventions in pre and postpartum groups also received: (i) a personalised letter acknowledging baseline readiness for change, personal health concerns, motivation to quit, comparison with other pregnant women who had successfully quit. (ii) relapse prevention kit within 2 weeks of completing the 28 week follow‐up survey. (iii) a booklet which discussed transition from pregnancy and factors that influence cessation and relapse; practical tips for high‐risk situations, strategies for avoiding self‐defeating reactions to slips, personal anecdotes from women who quit. (iv) 3 antenatal counselling phone calls: 2 weeks after the booklet and 1 and 2 months later. Calls were open‐ended but with standardised protocol based on motivational interviewing and with stage‐based objectives average 8.5 min.
3. The pre‐post group received an additional 3 counselling calls in the first four months after birth reinforcing themes from the Relapse Prevention booklet; 3 newsletters at 2, 6 and 12 months postpartum about health effects of environmental tobacco smoke and the importance of being a non‐smoking parent.

Outcomes

Smoking cessation; relapse prevention and patterns of smoking; biochemically validated with salivary cotinine at 28 weeks gestation; 8 weeks PP; 6 months PP; and 12 months PP. Response rates were 92% at 28 weeks; 91% at 8 weeks postpartum; 89% at 6 months postpartum; 87% at 12 months postpartum.
Salivary cotinine requested from all who reported abstaining for 7 days (< 20 ng/ml as cut off).

Notes

Process evaluation describes participation in specific intervention components, including relapse prevention.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

Unclear risk

B ‐ Unclear

Methods

Cluster randomised trial of provision of self help in 3 UK NHS hospital trusts, 1998‐2000. 118 midwives stratified according to workload and randomly allocated to provide intervention or control care. Computer‐generated randomisation, caregivers not masked to allocation. Sample size justification.

Participants

Women attending first visit; > 16 years; < 17 weeks gestation; literate in English. Smokers counted as those who reported "I smoke now", "I smoke now but have cut down since I thought I might be pregnant", or "I have stopped smoking since I thought I might be pregnant". Mean number of cigarettes per day at baseline I = 16, C = 15.1.

Interventions

Control group midwives continued to give routine advice according to usual practice.
Intervention midwives gave their usual care + spent at least 5 minutes introducing a series of 5 self help booklets "Stop for Good", based on Stages of Change theory, and gave them a copy of the first booklet. Subsequent booklets were mailed directly to the woman.

Outcomes

Self reported smoking cessation validated by urine cotinine (94%).
Perinatal outcomes: birthweight, gestation at birth. Stillbirths, perinatal, neonatal and childhood deaths not reported but available on request.
Attrition rate 8%.

Notes

Data not included in outcome tables as it was not adjusted for clustering. Good qualitative and quantitative process analysis of participants and midwives views of the intervention, which suggested poor implementation in some areas. Some concerns about contamination of control group.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

High risk

C ‐ Inadequate

Methods

Randomised, factorial design to identify the best way of encouraging the disclosure of smoking in pregnant women, in a HMO, Texas, 1988‐1990. No randomisation details.

Participants

Pregnant women enrolled in an HMO; >= 18 years; able to speak and read English; free of mental or sensory handicap; mental retardation or mental illness. 1078/1206 recruited. 121 refused others were < 18 or non‐English speaking.

Interventions

The 4 options compared were: (1) Format (i) a single yes/no question vs (ii) a multiple choice. (2) Channel (iii) oral vs (iv) written forms of the two questions. Oral vs written forms of the two questions.

Outcomes

Proportion of women smokers who disclosed smoking, biochemically validated with urine cotinine cutoff >= 50 ng/ml. No smoking cessation data.

Notes

Those who refused urine testing were classified as "smoking disclosed".
Misclassification of self‐report as non‐smoking was low in this study (3%).

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

Unclear risk

B ‐ Unclear

Methods

Quasi‐randomised (allocation by alternate days) trial of a new smoking cessation programme provided by public health nurses in the antenatal clinic of an Ontario (Canada) teaching hospital, compared with previous standard care.
No details of randomisation and unclear whether caregivers masked.

Participants

1028 women screened, 267 daily smokers (673 non‐smokers, 88 spontaneous quitters). Ineligible (39) late gestation; miscarriage; missed abortion; termination; malformation; mental illness; mental retardation. Refusal (4). 224 at baseline; 202 at 1 month follow up; 174 at 36 weeks; 190 at 4 weeks postpartum. Reasons for dropout: miscarriage (17), no further clinic visit (3), subsequent refusal (2), and preterm birth (16 ‐ all of these seen postpartum), and 12 lost to follow up. Mean cigarettes/day at intake I = 13, C = 12.8.

Interventions

Control: 3‐5 minutes explanation of the risks of smoking during pregnancy + pamphlet inviting women to a 2 hour cessation class in the evenings where the Windsor self help manual would be taught/provided.
Intervention (provided in English or French): 20 minutes 1:1 session with a public health nurse going through the Windsor self help manual program + follow‐up telephone call at a mutually agreed time. High intensity intervention.

Outcomes

Smoking cessation biochemically validated by urine cotinine.

Notes

No one attended the evening group class which was offered and was free.
Interesting discussion of women's perceptions of risk based on personal experiences. Process evaluation showed 93% received the intervention by second visit.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

Unclear risk

D ‐ Not used

Methods

Randomised trial with 4 arms whose aims were to improve the uptake of prenatal care and pregnancy outcomes, especially low birthweight, in a semi‐rural county of New York State, USA, 1978‐1980. No details of randomisation and unclear whether caregivers were masked to allocation.

Participants

Active recruitment of pregnant women with no prior live births + any of the following: < 19 years; single; low socioeconomic status, and any other women with no prior live births who wished to participate in the program. Exclusions were > 25 weeks gestation (though some were enrolled at 25 ‐ 29 weeks). Recruitment was through private obstetricians' offices, planned parenthood, public schools health department antenatal clinics and other health and human service agencies. 10% of target population entered prenatal care too late, 10% were not referred from private care, 500 interviewed, 400 participated; 47% < 19, 62% single, 61% low ses. Non‐Whites (46) excluded because too few; serious maternal or fetal conditions (20) excluded. Mean cigarettes per day at intake: C = 6.94, I = 7.65.

Interventions

Control (i) health and developmental screening of the baby at 12 and 24 months
(ii) (i) + free transport to pregnancy and well‐child visits (control)
(iii) (i) + (ii) + nurse home visits during pregnancy (intervention)
(iv) (i) + (ii) + (iii) + nurse home visits in child's first 2 years.
The focus of the home visiting was individualised from a detailed curriculum dealing with information on fetal and infant development; improvement of maternal diet; monitoring weight gain; elimination of cigarettes, alcohol and drugs; identifying pregnancy complications; encouraging rest, exercise and hygiene; preparing for labour birth and early newborn care. The intervention was also described as enhancement of informal support systems and linkage of parents to community services.
High intensity intervention.

Outcomes

Smoking cessation with biochemical cotinine validation in a subsample (n = 116). Data not included in high intensity outcome tables, as smoking was not the focus of the intervention.

Notes

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

Low risk

A ‐ Adequate

Methods

Trial of personalised smoking cessation interventions in a low socioeconomic population in Australia. No details of randomisation methods or whether caregivers were masked to allocation.

Participants

Women who identified as "current smokers" at their first antenatal visit at approximately 12 weeks gestation ("even a puff in the last 7 days"). Exclusion criteria: > 20 weeks gestation; twin pregnancy; not literate in English; drug dependency.
Mean cigarettes per day = 11 in both groups. Participation rate = 52% (n = 1013), with the majority of eligible nonparticipants refusing to enter the study.

Interventions

Control group received usual care, which included advice at the discretion of the caregiver, a group counselling session, and a pamphlet "Smoking & Pregnancy". The intervention group received as for the control group + 4 counselling sessions by a midwife specifically trained and employed to provide smoking cessation counselling, using cognitive behaviour therapy. Sessions included video presentation, interactive discussion and strong verbal messages. These were followed up with a 5 ‐ 10 minute personalised counselling session. High intensity intervention.

Outcomes

Self reported smoking cessation biochemically validated with urine cotinine at 36 weeks gestation, 6 weeks postpartum, and 6 months postpartum. Breastfeeding at 6 weeks and 6 months postpartum. General health assessment at first visit and 36 weeks. Preterm delivery rate, mean birth weight, proportion LBW (< 2500 g). Attrition rate = 15%.

Notes

Process evaluation showed 71% women in the intervention group received the full intervention.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

Unclear risk

B ‐ Unclear

Methods

A randomised trial comparing the impact on smoking cessation of two different packages of material mailed to current smokers and recent quitters at a large Boston HMO, USA, 1986‐1988. Randomisation using table of random numbers for one intervention. Clinic staff were not aware of the allocation. Allocation to intervention 2 was not randomised but offered to all eligible enrollees at one clinic: data on this intervention is not included in the review.

Participants

English‐speaking women enrolling in prenatal care; >= 18 years; < 24 weeks gestation who reported themselves as currently occasional or regular smokers or who had quit smoking in the previous 3 months. 1439/1442 screened (3 refused), 317 current/ recent smokers, 93 dropped out because of miscarriage, termination, moved away or left the HMO; 274 at second assessment and 224 at 8 weeks postpartum. 78 control and 71 intervention at baseline.

Interventions

Usual care: routine obstetric care, mailed list of community‐based smoking cessation resources other pregnancy‐related health education materials.
Intervention: pregnancy‐specific self‐help manual (Am Lung Assoc + Harvard Community Health Plan (HMO)) and audiotape on safe aerobic exercise and pregnancy‐related relaxation, mailed with other health‐related education. Smoking component emphasised behavioural strategies for quitting, issues and concerns specific to pregnant women, non‐smoking as part of a continuum of care in pregnancy; included a maintenance section for the postpartum period. Intervention based on cognitive behaviour therapy.

Outcomes

Smoking cessation for smokers and spontaneous quitters at mid‐pregnancy and 6 months, postpartum. Biochemical validation in 50% women.
Mean birthweight, low birthweight (< 2500 g) and very low birthweight (< 1500 g) outcomes.

Notes

Refusal of urine test = coded as smoking.
Substantial misclassification of non‐smoking self‐report at 6 months gestation 24% controls 21% intervention (and 30% in clinic where the intervention was more intensive). Data from two interventions combined in relapse prevention outcomes, so not included in tables.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

Low risk

A ‐ Adequate

Methods

A randomised comparison of two different minimal contact interventions to encourage smoking cessation and reduction during pregnancy, in women of low ses and low education, compared with usual care in an inner urban setting, Toledo, Ohio, USA, 1987‐89. Randomisation by dice, which did not work well (no allocation to usual care some of the time). Unclear whether allocation masked to caregivers.

Participants

"Typically low income, single and poor". 1164 approached, 486 (42%) were current smokers: 60% not enrolled (exclusion criteria not listed, though includes gestation > 28 weeks and refusal); 193 entered the study. Relatively low participation and 57% dropout from enrolment to completion.

Interventions

Control: usual care not specified or assessed but "usual for physicians to address this issue with participants at least one prenatal visit".
Intervention (i): tailored educational videotape 6.5 minutes, potential fetal risks, benefits if mother quit + pamphlet on how to quit and opportunity to ask questions of the health educator.
Intervention (ii): American Lung Association self help booklet (with brief overview and explanation) emphasising behaviour modification skills, relation techniques and the support of significant others, + opportunity to ask questions of the health educator.

Outcomes

Smoking reduction and cessation, validated by exhaled CO monitoring.

Notes

Program was developed with input from a questionnaire and open‐ended questions about the advantages and disadvantages of smoking when pregnant from local population to inform Health Belief Model used in program.
Commentary on the contextual factors in the lives of indigent women which lead them to have different perceptions about the relative importance of smoking.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

High risk

C ‐ Inadequate

Methods

An analysis within a subset of births in the RADIUS trial (births in Missouri, USA) to see whether ultrasound of the fetus at 18 ‐ 21 weeks and 31 ‐ 33 weeks promoted maternal smoking cessation during pregnancy. Randomisation by microcomputer based sequencing. Not clear whether caregivers were blinded to allocation.

Participants

53,367 pregnant women; ‐32,317 ineligible or excluded; leaving 21,050 ‐3,163 refused; ‐2,357 had miscarriage or change of provider; leaving 15,530 (7,812 intervention + 7,718 controls). subsequently ‐ 64 + 63 miscarriage, ‐131+121 records lost or women moved, leaving 7,617 + 7,534; 1,768 smoking (I) and 1,803 smoking (C). Smoking defined as any smoking within the year before their enrolment. Inclusion criteria = last menstrual period known within one week, gest age < 18 weeks, no plans to change providers. Exclusion criteria include medical or obstetric complications, planning an ultrasound for other reasons, twin pregnancy, not intending to continue pregnancy.

Interventions

Ultrasound only, at 18 ‐ 20 and 31 ‐ 33 weeks, no details about feedback to the mother or others. The women in the control group only had ultrasounds if ordered by their physician for medical reasons.

Outcomes

Self reporting smoking cessation, recorded on birth certificate, not biochemically validated (not included in outcome tables). Mean birthweight, preterm birth (< 36 weeks) and very preterm birth (< 33 weeks).

Notes

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

Unclear risk

B ‐ Unclear

Methods

A randomised comparison of the effects on health behaviours (including smoking) of providing specific verbal and visual feedback to the mother about fetal size, shape and movement during an ultrasound examination (or having the screen not visible and providing no specific feedback) at the first antenatal visit, in London, UK. No details of randomisation or whether caregivers blinded to allocation.

Participants

Pregnant women at 10 ‐ 14 weeks gestation; 18 to 32 years; stable relationship; Caucasian; 85% had planned pregnancy, at low risk of complications; 86% nulliparous. Exclusions: prior miscarriage or extended infertility investigations.

Interventions

Control: no/low feedback.
Intervention: high feedback about the fetus, with the fetus visible.

Outcomes

Self reported smoking cessation at 16 weeks gestation, without biochemical validation.

Notes

Not clear whether quitting was recent or not ‐ no time period specified.
3/62 low feedback group did not attend next visit at 16 weeks.
Cites evidence for the reliability of self report (Pettiti).

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

High risk

C ‐ Inadequate

Methods

Quasi‐randomised study (allocation by alternate weeks) of the effectiveness of a health education intervention provided by a psychologist from booking to birth, compared with standard care, at a large maternity hospital in England, 1978‐1979. Caregivers not masked to allocation.

Participants

Pregnant women registering for maternity care: 371/1645 were currently smoking at least 1 cigarette/day, 25 refused participation and 27 were lost because of miscarriage, termination or transfer to another care provider, leaving 319. No exclusions were mentioned or mean cigarettes/day pre‐pregnancy.

Interventions

Control: standard care not otherwise specified.
Intervention: counselling begun in antenatal clinic at 1st visit, with follow‐up visit 2 weeks after booking at home, then monthly to the birth, each visit 15 ‐ 20 minutes, (5 on average). Focus of counselling was help and support to change smoking, focus also on short and long term benefits; advice on stopping/cutting down, strategy planned with woman, follow up planned with clear objectives, involvement of other family members, friends and partner in support.

Outcomes

Smoking cessation, biochemically validated with exhaled CO and serum thiocyanate. Mean birthweight in subgroup smoking >= 5 cigarettes at booking.

Notes

Detailed account of the intervention in King and Eiser 1981.
Subgroup analysis seems not to have been a pre‐specified one.
Apparent problems with the thiocyanate measures and with loss of some data files (see paper).

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

High risk

C ‐ Inadequate

Methods

Evaluation of a program to train obstetric and family practice residents to give smoking advice during antenatal care, using pre‐ and post‐ training evaluation of their skills with a simulated patient, and exit interviews with women participating in a randomised trial of individualised smoking cessation counselling. 1988‐1990, Vermont, USA.

Participants

All residents providing (supervised) prenatal care, at the University of Vermont.

Interventions

Description of training and copies of 4 papers on smoking cessation advice + small group training by physician and psychologist during 1 hour workshop. Workshop: review of the project; description of advice and rationale for each step; use of protocol prompt sheet; video of advice being offered by GP and Obstetrician; role play with corrective feedback; basic care description; (individual training for residents unable to attend) + 30 minute refresher session with counsellor before the rotation + counsellor discussed actual progress and adherence.

Outcomes

Scores on video/simulated patient (blinded assessment, systematic scoring) significantly increased with no change in the time required to provide the advice; exit interviews showed good adherence to the protocol by 96/99 (intervention) and 66/67 (control) interviewees, as did women's proposed actions post‐intervention, also in exit interviews.

Notes

Useful for dissemination trials of smoking cessation in hospitals.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

Unclear risk

D ‐ Not used

Methods

A randomised trial comparing the effectiveness of individualised, but protocol‐based smoking cessation counselling provided by a specially trained health educator, compared with usual care, at the University of Vermont, USA, 1984‐1987. No details of randomisation and it is unclear whether caregivers were masked to allocation.

Participants

Women receiving prenatal care from obstetricians + nurse‐midwives, or residents; private and public including Maternal, Infant & Child clinic for under‐insured or non‐insured women (23% Medicaid in study); < 25 weeks pregnant (mean gest 13/40), smoking at least 1 cigarette a day, no exclusions mentioned. 808 interviewed, 33 refused, 175 sp quitters went into separate study of relapse prevention, leaving 300 + 300; (‐49: 27 miscarriage, 7 fetal deaths, 5 infant deaths), further losses were 24 + 24 changed care provider, 37 (I) + 4 (C) withdrew and 31 + 28 were lost to follow up. Mean cigarettes/day pre‐pregnancy I = 24.4, C = 25.1.

Interventions

Control: usual care, not otherwise specified.
Intervention, from a trained health educator: addressed concerns re smoking and pregnancy, health benefits of stopping, perception of the advantages and disadvantages of stopping, problem solving around those issues and coming to a decision, if yes to quitting formulating a plan, skills rehearsal + pregnancy‐specific booklet. Follow up at second antenatal clinic, 36 weeks and 6 week check (where infant health and parental role modelling was discussed) and re‐encouraged to quit.
Health educators given selected readings, discussion, rehearsal with psychologist + health educator (both former smokers) about smoking and smoking cessation counselling techniques + Am Lung Association training group for class leaders + 4 week pilot.

Outcomes

Smoking cessation at 36 weeks gestation, 75% biochemically validated with cotinine. Mean birthweight, low birthweight, other smoking‐related complications (pPROM, placental abruption and placenta praevia).

Notes

Sample size calculated for 10% increase (from 10% to 20%) in quitting.
Differential withdrawal in I and C groups a concern; good information collected on drop‐outs being different.
Allocation for fetal and infant deaths not reported.
No adjustment for misclassification.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

Unclear risk

B ‐ Unclear

Methods

Trial of relapse prevention counselling for spontaneous quitters, Vermont USA.. See Secker‐Walker 1994 for methodology details.

Participants

Those from Secker‐Walker 1994 who had stopped smoking spontaneously before their first prenatal clinic visit (n = 175, 89 (I) and 86 (C) among whom there were 5 miscarriages, 1 termination, 1 fetal death and 1 infant death leaving 85 (I) and 80 (C). Further losses were 15 transferred to other care, 9 dropped out and 8 lost to follow up.

Interventions

Control: usual care by own provider.
Intervention: see Secker‐Walker 1994 for training of health educators and cessation planning; in this group dealt with concerns about staying away from smoking, her perceptions of the advantages and disadvantages of maintaining cessation, problem‐solving and skills practice, + booklet; 39 weeks and postpartum visits focused on infant risks and benefits.

Outcomes

Smoking cessation, biochemically validated).
Mean birthweight, low birthweight, preterm birth.

Notes

Exclusion of fetal and infant deaths.
Biochemically validated smoking cessation showed substantial misclassification at 36 weeks in this study, more so than for the continuing smokers.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

Unclear risk

B ‐ Unclear

Methods

Trial comparing the added effectiveness for smoking cessation during pregnancy of a free videotape using peer role models, Vermont, USA, 1992‐1993. No details of randomisation. Caregivers not masked to allocation.

Participants

Women in a state supported clinic for underinsured women, currently smoking at least 1 cigarette/day, 7/67 refused leaving 30 (I) + 30 (C), 4 had miscarriage leaving 26 + 30, 3 lost to follow‐up and 7 moved to another care‐provider leaving 17 + 27 seen at 36 weeks. Mean cigarettes per day pre‐pregnancy = 22.6.

Interventions

Control: advice from obstetrician or nurse‐midwife + tip sheet on quitting.
Intervention: as above + 29 minute videotape of 4 women going through the process of quitting during pregnancy; talking about feelings; coping with weight gain; getting support, which could be borrowed and taken home. Based on social learning theory.

Outcomes

Smoking cessation in late pregnancy (36/40), biochemically validated with exhaled CO measurements..

Notes

Process evaluation included perceptions of the videotape contents and showed 53% viewed the videotape. 17% had no VCR, and 10% reported having no time.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

Unclear risk

B ‐ Unclear

Methods

A trial of structured physician's advice supported by individual counselling (I) provided to pregnant women during prenatal care compared with usual care (UC), Vermont, USA, 1988‐92. Sample size justification. The study included a relapse prevention component, reported separately. No details of randomisation. Caregivers could not be masked to allocation.

Participants

Woman attending the state‐supported (Maternal and Infant Care) prenatal clinic for underserved women or attending the Adolescent clinic for women 12 to 18 years.
544 women smoking at pregnancy onset approached:
21 refused
124 had quit spontaneously‐ relapse prevention trial;
399 into cessation trial ‐ 197 (I), 202 (UC);
14 miscarriages, 5 fetal deaths 5 infant deaths (allocation not reported);
34 in each group moved or transferred their care;
12 women withdrew from study (7 (I), 5 (UC))
17 delivered before 36 weeks (9 (I), 8 (UC))
135 (I) and 141 (UC) remained
114 (I) and 110 (UC) were contacted 1 year after birth, including 16(I) and 18 (UC) lost to follow up during pregnancy
Mean cigarettes/day pre‐pregnancy I = 26.1, C = 25.1.

Interventions

All participants received:
baseline questionnaire, measurement of exhaled CO, and brief standardised health risk message from a research nurse about the effects of smoking on the fetus and pregnancy.
UC was: physician acknowledged women's smoking , gave a rationale for quitting, strong recommendation to quit and provided smoking cessation booklet designed for pregnant women.
I was smoking cessation protocol provided by physicians trained in its use (Secker‐Walker et al, 1992): acknowledging the woman’s smoking, her exhaled CO level, any progress towards quitting, rationale for & unambiguous recommendation to quit, asking how she felt about quitting and acknowledging her response, asking how she could be helped and telling her about the counsellor, eliciting a commitment to change smoking behaviour before the next prenatal visit and referring her to the counsellor. The aim was to gain her agreement to set a quit date, a date when she would quit for 24 hours or a date when she would cut her consumption by half. Counsellor advised women on ways to accomplish the behaviour change.
2nd visit same with praise for those who had quit + referral to counsellor for help in staying quit, 3rd 5th 7 36 week visits a briefer protocol was followed with referral for those who wanted to change, praise for success and referral.

Outcomes

Smoking cessation maintained in late pregnancy (36/40) and 1 year postpartum, biochemically validated with exhaled CO and urine cotinine.
Mean birthweight
Low birthweight

Notes

Methods included a detailed process evaluation.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

Unclear risk

B ‐ Unclear

Methods

A randomised trial of an intervention to increase birthweight by changing maternal smoking, carried out in Baltimore, USA. No details of randomisation and it is unclear whether usual caregivers were masked to allocation.

Participants

Pregnant women who were smoking >= 10 cigarettes/day immediately prior to pregnancy (71% of whom were spontaneous quitters), < 18 weeks gestation, attending 52 private physicians and the hospital antenatal clinic. Heterogeneous population, including large inner‐city and suburban. 89% of those eligible were recruited n = 935, 463 (I), 472 (C). Mean cigarettes/day pre‐pregnancy I = 20.9, C = 20.7.

Interventions

Control: usual care, not further specified.
Intervention: at least 1 personal visit, supplemented by frequent mail and telephone contacts (at least 1 visit and 1 call/month) from 1 of 2 health educators (MEd level, trained in pregnancy counselling and smoking intervention), providing information, support, practical guidance and behavioural strategies for quitting.
Information on quitting + health risks of smoking was mailed every 2 weeks with 'homework' linked to telephone calls; group sessions were also available. There was a monthly lottery and in the last year of the study a monthly newsletter.

Outcomes

Smoking in late pregnancy, 97% biochemically validated with salivary thiocynate. Miscarriage; fetal deaths; mean birthweight; low birthweight; very low birthweight; % Apgar scores < 7 at 1 minute and 5 minutes; length and head circumference.

Notes

Change of criteria for enrollment after the first 185 as 35% of these had smoked < 10/day and 71% of that group had quit spontaneously with little relapse.
Detailed account of the intervention is in Nowicki et al 1984.
Group sessions in the intervention were not readily accepted.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

Unclear risk

D ‐ Not used

Methods

A trial of a smoking cessation intervention on women's 'stages of change' (precontemplation, contemplation, preparation and action) was assessed. No details of randomisation process.

Participants

Low income pregnant women enrolled in a state‐supported service for uninsured and under‐insured women, receiving care in a large obstetric group practice. 521 women smoking >= 1 cigarette/day at the onset of pregnancy enrolled, 349 (67%) completed assessments at 1st, 2nd and 36 week visits. Mean cigarettes/day pre‐pregnancy I = 22.8, C = 23.6.

Interventions

Control: 3 minute physician‐delivered protocol at first visit, acknowledging her smoking, concerns re quitting or staying quit; strong recommendation to quit + cessation pamphlet designed for pregnant women.
Intervention: as control + quit date or date to cut down set + on‐site counselling, 10‐30 minutes at 1st, 2nd, 3rd 5th and 36 week visits from trained obstetric nurse: encouragement and reinforcement of small changes, problem solving around barriers to cessation, and prevention of relapse, including dealing with other smokers, coping with the urge to smoke, withdrawals symptoms, weight gain, eliciting support for quitting.

Outcomes

Shifts in 'Stage of change' at 2nd visit and 36 weeks gestation.
No smoking cessation data to include in tables.

Notes

Comment made that stages of change at the first visit are not sustained.
"Enthusiasm for behaviour change may wane towards the end of the gestational period when attention may be focused on labour
and delivery".
Pattern of 'stages' at first visit different from community‐based studies i.e. more women were in the later stages than would be expected at the study onset.
No difference in late pregnancy.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

Unclear risk

B ‐ Unclear

Methods

Trial of proactive telephone peer support in a large obstetric practice in Vermont, US, 1996‐7. No description of randomisation procedure. Caregivers not able to be masked to allocation.

Participants

Women reporting smoking at least 1 cigarette in the past week at their first antenatal visit, were approached. Refusal rate = 19%. Women tended to be white, English speaking, and of lower income and education. No exclusion criteria specified. Control n = 74, Intervention n = 77. Mean cigarettes/day before pregnancy I = 22.6, C = 20.2.

Interventions

Control group received brief smoking cessation advice from a MW/Obst at each of the 3 prenatal visits and stage appropriate printed materials. MWs/Obst were provided with a 45 minute training session. The intervention group received the same as the control group + offered telephone peer support (from a female ex‐smoker, who received 8 hours of training) for women with moderate or high intentions of quitting. who called the participant within several days to provide support for positive changes in smoking behaviour.

Outcomes

Self reported abstinence at 28 ‐ 34/40 gestation, defined as no smoking for the past 7 days, biochemically validated with urine cotinine measurement. Movement in stages of change and proportion of smoking reduction by more than 50%. Attrition = 16 (10.6%).

Notes

Process evaluation showed 53% received the peer intervention.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

Unclear risk

B ‐ Unclear

Methods

Trial of individualized stage of change, motivational smoking cessation intervention ("one‐to‐one"), with personalized feedback for "resistant" pregnant smokers, in 3 large multispecialty clinics in Texas, US. Random allocation determined by a computer generated list. Unclear whether caregivers masked to allocation.

Participants

Women who continue to smoke at 28 week gestation, after having counselling and 8 self help booklets earlier in pregnancy care. Inclusion criteria were women fluent in English, over 18 yrs, over 20 weeks gestation at first an visit, and smoke more than 5 cigarettes per week prior to pregnancy. All women had group insurance. Eligibility interview participation rate 97%. All eligible included in randomised sample (n = 269), as data collection and implementation were adopted as routine procedures, and required to formal written consent. Women in the intervention group had significantly higher proportion of women smoking > 61 cigarettes/week before pregnancy (I = 57.9%, C = 43%) and a higher proportion of partners who smoke (I = 69.6%, C = 62.5%).

Interventions

All women smoking at intake (< 20 weeks), were provided with MI counselling and motivational self help books, based on "stage of change" program shown to be effective by Ershoff et al. Women still smoking at 28 weeks were randomised to this study. The high intensity intervention group (and their partners) then received: a 20‐30 min MI telephone counselling call (conducted by trained counsellors and nurse health educators), a personalised, stages of change based feedback letter, and a final MI‐base telephone call conducted 4 ‐ 5 days after the feedback letter was sent.

Outcomes

Self reported smoking cessation at 34 weeks gestation, validated by an anonymous urine cotinine subsample. Postpartum follow up (6w, 3m, 6m) interview response rate 61% (data collected from a separate survey, with financial incentives). Movement in "Stages of Change". Breastfeeding rates and general health behaviours obtained but not reported.

Notes

Only 55% of the experimental group received the full intervention (32% were never able to be reached). Implementation analysis suggested an effect in women who received full implementation: 43% vs 34% control group.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

Unclear risk

B ‐ Unclear

Methods

Trial of personalised, computer generated, smoking cessation messages, in 2 university hospitals in North Carolina & Michigan, USA, Dec 1996‐97. Randomisation by computer algorithm. Unclear whether caregivers masked to allocation.

Participants

Women who have "smoked 100 cigarettes in their lifetime and still smoking" or "had quit since becoming pregnant", completed a self administered computer screening program to determine eligibility (no details of inclusion or exclusion criteria). 173 women participated. Mean cigarettes/day smoked before pregnancy I = 20.3, C = 18.7 (ns).

Interventions

Control group received "a pregnant woman's guide to quit smoking" at the first visit. The intervention group entered personal data into a hand‐held computer at antenatal visits, which subsequently generated personalized tailored messages, which were posted to the woman.

Outcomes

Self reported smoking cessation validated by urine cotinine at first visit, 24/40 and 6 weeks postpartum. Attrition rate 14% in control group, and 15.2% in experimental group.

Notes

Numbers in paper inconsistent: I = 88, C = 85 in methods section, I = 104, C = 87 in results section. No justification for change of denominators ‐ assumption was ITFV were smokers.
Participant evaluation of using hand‐held computers and reactions to computerised materials.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

Unclear risk

B ‐ Unclear

Methods

Pilot study of home based motivational interviewing for smoking cessation in a Glasgow Hospital, Scotland, March‐May 1997. Consenting women stratified and randomly allocated to 2 equal groups using blinded telephone allocation. Unclear whether caregivers masked to

Participants

Self reported women who identified as smokers on a questionnaire at antenatal clinic booking. Participation rate 75%, 27 refused. (n = 100). Mean cigarettes/day pre‐pregnancy I = 19.6, C = 18.1.

Interventions

The control group received usual advice from their prenatal providers, which should include information about smoking. The intervention group received 2 ‐ 5 motivational interviewing sessions, based on stages of change, in the clients home conducted by a midwife trained in smoking cessation counselling. High intensity intervention.

Outcomes

Self reported smoking cessation, at 27/40 or more, with urine cotinine validation in 93%. Mean birthweight, preterm births. Ranking interviews measured movement around the "cycle of change". Detailed evaluation of participant and midwifery views of interventions. Attrition rate 2%.

Notes

Good process evaluation of implementation quality according to Millers rating tool, showed 79% of women in the intervention group received at least 2 counselling sessions, and less than 20% of the control group recalled being given smoking information at the time of booking.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

Low risk

A ‐ Adequate

Methods

Trial of smoking cessation counselling and information packs in a large public antenatal clinic, in Rotunda Ireland, during 3 months in 1995. Randomisation by random number tables, allocation concealed by opaque sealed envelopes and restricted in groups of ten. Intervention provided by trained facilitator, with staff unaware of allocation.

Participants

Inclusion criteria: women who currently smoke or had spontaneously quit since becoming pregnant; have a viable pregnancy; and intend to deliver in the hospital. Participation rate = 81% (n = 418). Intervention group were less likely to have spontaneously quit, or be employed. Mean gest at first visit I = 15.5, C = 15.3. Number of daily cigarettes at intake: 1‐9 I = 61, C = 54; 10‐19 I = 74, C = 73; 20+ I = 68, C = 65.

Interventions

The control group completed a questionnaire at first visit, followed by routine prenatal advice on a range of health issues, from midwives and obstetricians. The intervention group received as for the control group + structured one to one counselling by a trained facilitator (based on stages of change theory); partners invited to be involved in the program; an information pack; and invited to join a stop smoking support group. A carbon monoxide monitor was available for the intervention group, to quantify smoking habit and act as a motivational tool. High intensity intervention.

Outcomes

Smoking cessation at delivery, biochemically validated by exhaled CO. Reduction in mean cigarettes/day, quit attempts, comparisons of quitters and non quitters at various stages.
Infant outcomes (singleton births): delivery type, mean gestation, mean birthweight, proportion LBW (2500 g), preterm births, NNICU admissions, infant outcomes at 3 months.
Attrition at delivery: I = 6.2%, C = 8.6%.

Notes

Good process analysis and participant feedback of program implementation. A high baseline smoking prevalence rate (58.7%). Limited exhaled CO measurement on postnatal ward.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

Low risk

A ‐ Adequate

Methods

Quasi‐randomised trial of smoking cessation interventions (allocation to 1 of 4 arms, 3 intervention and 1 control, by date of enrollment for care, with the four time blocks assigned randomly) in women smoking at the time of the 18 week ultrasound scan, at a regional hospital in Norway, 1988.
Caregivers not masked to allocation.

Participants

283 women reported current smoking and wanted to quit. (mean 9‐11 cigarettes/day) at the 18 weeks scan: 200 recruited, 50 in each arm. 1/3 receiving private obstetric care.

Interventions

Control: not specified.
Intervention (i): information provided by a physician to women in groups of 10 about the harmful effects of smoking on mother and child;
(ii) 2 page pamphlet mailed 3 weeks after the ultrasound scan, with information on the harmful effects of smoking + advice on how to quit;
(iii) smoking cessation group of 12 ‐ 13 people; 5 x 2 hour meetings over 5 weeks, offered a cognitive behaviour modification program, including self‐monitoring, stimulus control, response control, reinforcement control and maintenance strategies, run by a clinical psychologist.

Outcomes

Smoking cessation assessed immediately after the intervention, biochemically validated but not reported. intervention arms.

Notes

Biochemical validation of smoking status using salivary thiocyanate was carried out but not reported in the paper.
Doctor information group treated as 'control' for the other interventions because of minimal impact at either time.
Smoking assessed 12 months (96% response rate to questionnaire) after the intervention showed sustained differences by allocation though more than half the quitters had relapsed in the behaviour modification group.
Process evaluation showed 20% women attended only the first of the 6 group meetings, and 12% of the women in the brochure group did not read them.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

High risk

C ‐ Inadequate

Methods

Quasi‐randomised trial of cognitive‐behavioural modification, (using RA Windsor's self‐help manual translated into Norwegian) to promote smoking cessation in women smoking heavily at the time of the 18 week ultrasound scan, in Oslo 1990‐1991. No details of randomisation and caregivers not masked to allocation.

Participants

Pregnant women attending the National University Hospital Oslo at 18 weeks for ultrasound, and smoking 10 cigarettes/day. No exclusion criteria mentioned and no refusals. 112 women recruited (1800 births/year, study over 15 months). Pre‐pregnancy mean cigarettes/day: I = 8, C = 11.

Interventions

Control: information on the negative effects of smoking + encouragement to quit, reinforced by a pamphlet, provided at the time of the ultrasound examination.
Intervention: offered the Windsor self‐help manual describing a 10 day program, 2 weeks later reminder. Letter + encouragement and appointment for 32 week scan + reinforcement at the 32 weeks scan + 2 weeks later a further letter.
Both intervention and control information were provided by obstetrician or midwife.

Outcomes

Smoking cessation in late pregnancy. No biochemical validation.

Notes

Evidence is provided for an increase in smoking compared with 18 weeks, especially in the control group.
Process evaluation suggested that the acceptance of the manual was low (mean score 2.6 on 7 point scale) and that it was staff involvement which had the most impact.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

High risk

C ‐ Inadequate

Methods

Randomised trial of hypnosis for smoking cessation and reduction among women still smoking at the time of the 18 week ultrasound scan in a Norwegian hospital, 1990‐1993. Randomised by random number tables, with usual caregivers masked to allocation.

Participants

Women were offered participation if still smoking at 18 week ultrasound visit, (after explanation including potential allocation to control) and then randomised after signing. Expected numbers of women in the recruitment period were 630, 158 (25%) agreed to participate. Of 80 allocated to intervention 13 did not receive an appointment in time, 15 did not attend leaving 52. Mean cigarettes/day prior to pregnancy I = 15.6, C = 15.0.

Interventions

Control: "routine pregnancy health care".
Intervention: anaesthesiologist provided 2 x 45 minute sessions at 2 week interval of a protocol‐based recipe (Handbook of the American Society of Clinical Hypnosis); the tape played after hypnosis was established emphasised the unpleasant effects of smoking, affirmed her wish to quit, encouraged her will and capacity to quit, and instructed her in meeting cravings with relaxation techniques and self‐hypnosis, explained during the session. Second visit tape was different with more weight on her capacity and taking control. Both tapes avoided "moralizing about her responsibility for pregnancy outcome".

Outcomes

Self reported smoking cessation, reduction and increase at end of pregnancy, not biochemically validated.
Perinatal deaths.

Notes

Process evaluation did not rate the intervention highly: mean score of 2.05 on a 7 point scale.
Norway

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

Low risk

A ‐ Adequate

Methods

Trial of a structured, cognitive‐behavioural, smoking cessation program for pregnant women delivered by usual care providers in a public hospital antenatal clinic in Newcastle, Australia, 1990‐1991. Randomised after consent by precoded questionnaires in opaque envelopes, with a computer generated sequence.

Participants

1909 pregnant women were screened at the first visit (approximately 12 weeks gestation). Classified as a smoker if they answered yes to the question "Are you a smoker?": 725 smokers (38%), ‐ 187 ineligible > 26 weeks, ‐ 47 too ill or disturbed, ‐11 other reasons left 538. 293 agreed to take part. 7 (I) + 7 (C) withdrew, 10 + 10 had a miscarriage or termination, 4 + 3 gave birth preterm, leaving 125 + 127. Baseline smoking data not specified.

Interventions

Control: Doctor and Midwife both informed women that smoking was an important cause of pregnancy problems and they should stop; Midwife provided a package (sticker, pamphlet on risks of smoking and 2 page cessation guide), none of which were specifically tailored to pregnant women.
Intervention based on cognitive behaviour therapy: (i) 2‐3 minute standardised risk information from Doctor + 14 minute video on risk information rebuttal of barriers to quitting, cessation tips + 10 minute standardised information and counselling from Midwife after the video, using a flip chart, with negotiation of a quit date whenever possible + self‐help manual on risks, barriers and cessation + 4 packets of confectionary gum + lottery chance (4 prizes) for biochemically validated abstainers at the next visit + social support from accompanying adult (partner/friend/other) vis support tip sheet, contract and form letter + chart reminder vis sticker in the medical record + form‐letter + sticker from 1st visit Midwife mailed within 10 days + 2nd visit and 34 to 36 week visit 5 minute counselling from Midwife and 1‐2 minute risk advice from Doctor. Women still smoking at 34‐36 weeks were advised to attend an external cessation course.

Outcomes

Smoking status at mid and late pregnancy and postpartum, biochemically validated with salivary cotinine (I = 86%, C = 78%).

Notes

Midwives involved in recruitment to the trial had variable 'success'.
Overall participation was quite low (54%).
Cotinine data inconsistent with self‐report was 52% in controls and 12% in the intervention group.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

Low risk

A ‐ Adequate

Methods

A randomised trial, comparing the effectiveness of 2 smoking cessation interventions with standard care, in public health clinics in Birmingham, Alabama, USA 1983‐1984. No details of randomisation. Usual caregivers masked to allocation. Sample size justification.

Participants

1838 pregnant women were screened, 460 current smokers (">= 1 cigarette in the last 7 days"), ‐30 antenatal care entry >= 32 weeks, ‐9 left system or moved, ‐10 miscarriage or termination ‐10 went to group discussions (this intervention abandoned), leaving 102 I1), 103 (I2) and 104 (SC). No baseline data on cigarettes/day.

Interventions

Control: 2‐3 minutes within a group prenatal education session at the 1st visit, when maternity clinic staff recommend quitting.
I1: 10 minute standardised counselling session from a health educator (B Comm H Ed) + Am Lung Assoc "Freedom from smoking" (ALA) manual (17 day self‐directed plan for quitting) + "Because you love your baby" pamphlet on the dangers and risk of smoking and the benefits of quitting.
I2: as for I1 except that the manual was "A pregnant woman's self‐help guide to quit smoking" (instead of the ALA manual).

Outcomes

Smoking cessation or reduction, biochemically validated by salivary thiocynate, at mid‐pregnancy and within 48 hours of birth.

Notes

"Multiple attempts were made to bring pregnant smokers together for a peer‐led, focused group discussion: not feasible in this setting".
All those lost to follow up were considered smokers.
Pre‐trial assessment showed no nurses (n = 80) had smoking cessation training and less than 20% felt confident to advise women on how to stop.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

Unclear risk

B ‐ Unclear

Methods

Trial of an enhanced cognitive behaviour therapy intervention, to assist in smoking cessation and smoking reduction during pregnancy in women attending public maternity clinics at a large hospital in Birmingham, Alabama, USA, 1986‐91. Randomisation by a computer‐generated system. Caregivers not masked to allocation.

Participants

4352 pregnant women screened at approximately 4 weeks gestation, 1381 (31.7%) reported smoking at conception, 1171 current smokers (smoked 1 cigarette even a puff in the last 7 days), ‐110 ineligible by entry to care > 32 weeks, did not complete first visit, did not return, in earlier trial, prisoner, reading level too poor, leaving 1061 of whom 67 refused leaving 493 (I) and 501 (C), ‐93 + 87 miscarriage, termination or withdrawal from public care, leaving 400 (I) + 414 (C). NS difference in baseline cotinine.

Interventions

Control: 2 minute talk in 30 minute group session at first antenatal visit in which women were urged to quit and given 2 pamphlets: "Smoking and the two of you'"+ "Where to find help if you want to stop" including the name, contact phone number and cost of their local program.
Intervention based on cognitive behaviour therapy: 15 minute standardised cessation skills and risk counselling session from trained female health education counsellor + 7 day self‐directed cessation guide on how to quit written at 6th Grade level + reinforcement (chart sticker) + letter from Doctor within 7 days + 'buddy' letter, contract and tip sheet + monthly newsletter with testimonials, cessation tips and additional information on risks.

Outcomes

Smoking cessation at 32 weeks gestation, biochemically validated with salivary thiocyanate.

Notes

Separate paper on spontaneous quitters (Lowe et al, 1997).
All those lost to follow up were counted as continuing smokers.
Data on gestation and birthweight were collected but the published analysis is by stopping smoking and the timing of cessation rather than by allocation, so not included in outcome tables.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

Low risk

A ‐ Adequate

Methods

Evaluation trial of behavioural impact of new patient education methods ("SCRIPT"), provided by trained medicaid maternity care staff members, in Alabama, USA, 1997‐2001. 17 eligible counties (> 50 pregnant smokers per year) stratified (% black: white pop; % pregnant smokers) into 8 clusters and 50% randomly selected (no details). Usual caregivers not able to be masked to allocation.

Participants

Women screened at first visit (9 ‐ 12 weeks gestation) for self‐reported smoking, validated by salivary cotinine. 2 separate phases: participation rate phase one (1997) = 95% (n = 93), phase 2 (1998) participation rate = 60% (n = 172). Phase one and 20% phase 2 group combined to form control group (n = 126), 80% phase 2 group (n = 139) formed intervention group. Both groups smoked approximately 10 cigarettes/d at baseline.

Interventions

Nurses, social workers and WIC administrators received orientation sessions. Partnerships were developed for program implementation. Control group patients had self report smoking status ("Ask", and a saliva sample, and counselling ("advise"). Intervention (based on cognitive behaviour therapy) group were provided with 2 further components "assist and arrange", which included a motivational video to take home to show partners, "A pregnant woman's guide to quit smoking", and < 5 min counselling session.

Outcomes

Self reported smoking status at 60 days after first visit, validated by salivary cotinine. Significant (> 50%) reduction in baseline cotinine (harm reduction measures). No quit attempts. Attrition rate 13% (n = 34), counted as smokers.

Notes

Mixture of RCT/sequential study with main control group being recruited in phase one of the study to identify representative sample, and small additional control group recruited in phase 2 with the intervention group. Good process evaluation showed nearly 100% experimental group received the intervention, confirming the feasibility of routine delivery by regular staff.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

High risk

C ‐ Inadequate

Methods

Double‐blind, placebo controlled trial of nicotine replacement therapy (patches) in pregnant women in a Danish obstetric hospital. Women consenting to participate were randomly assigned in blocks of 6, to nicotine or placebo patches. The investigation team were blinded to allocation.

Participants

Healthy women less than 22 weeks gestation who smoked more than 10 cigarettes per day after the first trimester, were invited to participate n = 611. Participation rate 41% (n = 250).Mean cigarettes per day at intake I:n = 13.4, C: n = 14.2.

Interventions

Both groups received strong smoking cessation advice and counselling from a midwife, reinforced with printed materials. The control group received a placebo patch. The intervention group received 16 hour 15 mg nicotine patches for 8 weeks and 10 mg for 3 weeks.

Outcomes

Self reported abstinence of at least 7 days at 2nd, 3rd, and 4th prenatal visits, validated by salivary cotinine measurement. Telephone follow up at 3 and 12 months postpartum (self report).
Mean birthweight, low birthweight (,2500 g), preterm delivery.

Notes

Very low recruitment, with non‐participants smoking more cigarettes per day. Compliance lower for placebo group, who may have guessed allocation. Limited details on 3 months and 1 year follow up.

Risk of bias

Bias

Authors' judgement

Support for judgement

Allocation concealment?

Low risk

A ‐ Adequate