Methods

Study design: RCT.

Duration of study: 1999.

Participants

Setting: Glasgow Royal Maternity Hospital, Scotland.

Inclusion criteria: healthy women who had experienced a normal pregnancy, presented at term in spontaneous labour and were eligible for admission to the Midwives Birth Unit.
Exclusion criteria: women with risk factors.
Participants randomised: 334 women (157 admission CTG (referred to as 'control group' in paper), 177 intermittent auscultation (referred to as 'study group' in paper)).

Randomisation on admission in labour.

Interventions

Admission CTG: a routine 20‐minute period of EFM at the time of admission.

Intermittent auscultation: the fetal heart was auscultated during and immediately following a contraction for a minimum of 60 seconds.

Outcomes

Outcomes considered in the review and reported in or extracted from the study:

• caesarean section;

• instrumental vaginal birth;

• continuous EFM during labour;

• amniotomy;

• oxytocin for augmentation of labour;

• epidural;

• fetal blood sampling;

• fetal and neonatal deaths;

• Apgar score < 7 at or after 5 minutes;

• admission to neonatal intensive care.

Notes

Unpublished data to permit re‐inclusion of women to groups as randomised kindly provided by author.

This study was funded by North Glasgow University Hospitals NHS Trust.

Declaration of interest were not mentioned in the trial.

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Low risk

"...computer‐generated in order to allocate participants equally between the two groups..."

Allocation concealment (selection bias)

Low risk

"...sequentially numbered, sealed opaque envelopes, which contained allocation to the appropriate group."

Blinding of participants and personnel (performance bias)
All outcomes

High risk

Although not documented, we judged, given nature of intervention, that women and clinicians were not blind to the interventions used.

Blinding of outcome assessment (detection bias)
All outcomes

High risk

Not blinded.

Incomplete outcome data (attrition bias)
All outcomes

Low risk

Loss to follow‐up: in the trial report 22 women (7%) are excluded from the analysis (21 women entered into the study and found not to be in labour and 1 randomisation card missing). However, data for these 21 of 22 women were identified and extracted subsequently by the trial author and kindly provided to the review team.

Selective reporting (reporting bias)

Low risk

All outcomes stated in the methods section were reported adequately in results.

Other bias

Low risk

None identified.

Methods

Study design: RCT.

Duration of study: 1997 to 2001.

Participants

Setting: National Maternity Hospital in Dublin, Ireland.

Inclusion criteria: women were eligible for inclusion if they were admitted in labour, a singleton pregnancy, fewer than 42 completed weeks of gestation, no suspicion or evidence of antenatal fetal compromise, no adverse obstetric history, clear amniotic fluid, and maternal temperature of 37.5°C or less at admission.
Participants randomised: 8628 women (4320 admission CTG, 4308 intermittent auscultation).

Randomisation on admission in labour.

A relatively small number (fewer than 5%) of women who had a previous caesarean section and who went into labour prior to 37 completed weeks' gestation were included in this study and were randomised. The trial author kindly provided data separately for the outcomes for women (i) between 37 and 42 completed weeks with (ii) an absence of previous caesarean section and these data were used in the main analyses for this review. Sensitivity analyses were conducted in which the outcomes for all randomised women were used.

Interventions

Admission CTG: a 20‐minute admission CTG immediately after early amniotomy done on diagnosis of labour in women presenting to the delivery ward.

Intermittent auscultation: intermittent auscultation was used for 1 minute after a contraction every 15 minutes in the first stage and every 5 minutes in the second stage of labour. This was done after early amniotomy on diagnosis of labour in women presenting to the delivery ward.

Outcomes

Outcomes considered in the review and reported in or extracted from the study:

• caesarean section;

• instrumental vaginal birth;

• continuous EFM during labour;

• oxytocin for augmentation of labour;

• epidural;

• fetal blood sampling;

• fetal and neonatal deaths;

• Apgar score < 7 at or after 5 minutes;

• neonatal seizures;

• admission to neonatal intensive care;

• length of stay in neonatal intensive care (hours).

Notes

See Participants (above)

The study was funded by the Research Committee of the National Maternity Hospital, Holles St, Dublin, Ireland.

Declarations of interest: none declared.

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Low risk

"...the randomisation sequence was from a commercial package 10 and used a fixed block size of 100. It was changed after 2621 patients had been recruited, and was generated by the National Perinatal Epidemiology Unit with random block sizes of 100–250."

Allocation concealment (selection bias)

Low risk

"...sealed, opaque, sequentially numbered envelope."

Blinding of participants and personnel (performance bias)
All outcomes

High risk

Although not documented, we judged, given nature of intervention, that women and clinicians were not blind to the interventions used.

Blinding of outcome assessment (detection bias)
All outcomes

Low risk

"...Data were entered and neonatal assessment was made without knowledge of the randomised assignment."

Incomplete outcome data (attrition bias)
All outcomes

Low risk

Loss to follow‐up = 22 (0.5%); admission CTG 26 (0.6%). Intermittent auscultation.

For outcome 'pH less than 7 or BD/E > than 12 mmol/L' 7.5% and 7.8% data missing for admission CTG and intermittent auscultation respectively.

Selective reporting (reporting bias)

Low risk

All outcomes stated in the methods section were reported adequately in results.

Other bias

Low risk

None identified.

Methods

Study design: RCT.

Duration of study: not stated.

Participants

Setting: Dundee, Scotland.

Inclusion criteria: "Women were eligible to join the study if they were booked for hospital delivery, attended a hospital or community based consultant led clinic in the third trimester of pregnancy, and had no obstetric complications at that visit that would warrant continuous intrapartum monitoring of FHR (pre­ eclampsia or hypertension in previous or index pregnancy; essential hypertension; diabetes (insulin dependent or gestational); suspected intrauterine growth restriction; placental abruption or praevia or vaginal bleeding of unknown origin; multiple pregnancy; fetal malformation; previous caesarean section; breech presentation; or rhesus isoimmunisation)."
Participants randomised: 3752 women randomised. "No data collected n = 1" (1866 admission CTG, 1885 intermittent auscultation).

A total of 3752 women were recruited to the study and randomised during the third trimester. However, some women developed an obstetric complication between randomisation and admission in labour that warranted continuous FHR monitoring in labour, such that only 2367 women were judged to be low‐risk when in labour (1186 admission CTG, 1181 intermittent auscultation). The trial author kindly provided data separately for the outcomes in this subgroup of women and these data are used in the main analyses in this review. Sensitivity analyses were done in which the outcomes for all randomised women were used.

Interventions

Admission CTG: a 20‐minute CTG on admission in spontaneous uncomplicated labour.

Intermittent auscultation: auscultation of the fetal heart with a hand‐held Doppler device during and immediately after at least 1 contraction.

Outcomes

Outcomes considered in the review and reported in or extracted from the study:

• caesarean section;

• instrumental vaginal birth;

• continuous EFM during labour;

• amniotomy;

• oxytocin for augmentation of labour;

• epidural;

• fetal blood sampling;

• fetal and neonatal deaths;

• evidence of fetal multi‐organ compromise within the first 24 hours after birth;

• Apgar score < 7 at or after 5 minutes;

• hypoxic ischaemic encephalopathy;

• admission to neonatal intensive care;

• length of stay in neonatal intensive care (days).

Notes

See Participants (above)

This study was funded by Chief Scientists Office of the Scottish Executive, Edinburgh.

Declarations of interest: none declared.

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Low risk

"...commercially available computer randomisation program."

Allocation concealment (selection bias)

Low risk

"The allocation was placed in a sealed envelope..."

Blinding of participants and personnel (performance bias)
All outcomes

High risk

Although not documented, we judged, given nature of intervention, that women and clinicians were not blind to the interventions used.

Blinding of outcome assessment (detection bias)
All outcomes

Low risk

"The data analysts were blind to the randomisation code."

Incomplete outcome data (attrition bias)
All outcomes

Low risk

Loss to follow‐up for the primary outcome of metabolic acidosis was high (admission CTG N = 310, 26% and intermittent auscultation N = 321, 27%). However, metabolic acidosis was defined as "pH less than 7.20 or BD (Base Deficit) > than 8 mmol/L". Data were unavailable for the outcome metabolic acidosis as defined in this review, i.e. 'pH less than 7 or BD/E > than 12 mmol/L', therefore this study does not provide data for this outcome in this review. All other outcomes had low rates of missing data, hence rating as low risk of bias.

Selective reporting (reporting bias)

Low risk

All outcomes stated in the methods section were reported adequately in results.

Other bias

Low risk

"Between randomisation during the third trimester of pregnancy and admission in labour, 1384 women (37%) developed an obstetric complication that warranted continuous fetal heart rate monitoring in labour".

A total of 3752 women were recruited to the study and randomised during the third trimester. However, some women developed complications between randomisation and admission in labour, such that only 2367 women were judged to be low risk when in labour (1186 admission CTG, 1181 intermittent auscultation). There are similar levels of attrition in both groups due to development of complications suggesting that allocation concealment remained intact. The trial author kindly provided data separately for the outcomes in this low‐risk subgroup of women and these data are used in the main analyses in this review.

Methods

Study design: RCT.

Duration of study: 2002 to 2006.

Participants

Setting: Buckinghamshire, England.

Inclusion criteria: labouring women considered to be "low risk" of fetal or maternal complications on admission.

Exclusion criteria: any minor maternal medical complication, e.g. diabetes or essential hypertension; previous caesarean section; preterm labour (< 37 completed weeks); multiple pregnancy; prolonged pregnancy (> 42 completed weeks); prolonged membrane rupture (more than 24 hours); induction of labour; meconium‐stained liquor; maternal pyrexia; rhesus sensitisation; polyhydramnios; oligohydramnios; pre‐eclampsia or blood pressure over 140/90 mmHg; abnormal presentation or lie (e.g. breech, transverse); high head (5/5ths palpable per abdomen); antepartum or intrapartum haemorrhage; known or suspected intrauterine growth retardation; any known or suspected fetal medical complication; abnormal Doppler artery velocimetry; known fetal malformation; poor obstetric history (e.g. history of stillbirth); un‐booked.
Participants randomised: 582 women randomised (298 admission CTG, 284 intermittent auscultation).

Randomisation on admission in labour.

Interventions

Admission CTG: a 15‐minute CTG on admission in spontaneous uncomplicated labour.

Intermittent auscultation: auscultation of the fetal heart for one continuous minute using a Pinard stethoscope or Doppler ultrasound device, after a contraction, at least every 15 minutes in the first stage of labour, and every 5 minutes in the second stage of labour.

Outcomes

Outcomes considered in the review and reported in or extracted from the study:

• caesarean section;

• instrumental vaginal birth;

• oxytocin for augmentation of labour;

• fetal and neonatal deaths;

• Apgar score < 7 at or after 5 minutes;

• admission to neonatal intensive care.

Notes

See Participants.

The study was funded by Buckinghamshire Hospitals NHS Trust's Research Department and through the establishment of a research midwife role within the maternity unit.

Declaration of interest not mentioned.

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Low risk

"...via a random number table."

Allocation concealment (selection bias)

Low risk

"Allocation to control and experimental arms was via opening of the next envelope in a series of sequentially numbered envelopes."

Blinding of participants and personnel (performance bias)
All outcomes

High risk

Although not documented, we judged, given nature of intervention, that women and clinicians were not blind to the interventions used.

Blinding of outcome assessment (detection bias)
All outcomes

Unclear risk

Not stated.

Incomplete outcome data (attrition bias)
All outcomes

Low risk

All outcome data reported with exception of "augmentation with oxytocin" where missing data were low (admission CTG N = 2, 0.7% and intermittent auscultation N = 4, 1.4%).

Selective reporting (reporting bias)

Low risk

All outcomes stated in the methods section were reported adequately in results.

Other bias

Low risk

None identified.