Primary outcomes

1.  Blood loss of 1000 mL or more after birth   

2.  Manual removal of the placenta

Secondary outcomes

1. Blood loss of 500 mL or more after birth

2. Mean blood loss

3. Mean duration of the third stage of labour

4. Retained placenta for more than 60 minutes or as defined by trial author

5. Blood transfusion

6. Maternal haemoglobin less than 9 g/dL at 24 to 48 hours post‐delivery or blood transfusion

7. Use of additional uterotonics during or after the third stage of labour

8. Maternal death or severe morbidity (e.g. operative procedures, organ failure, intensive care unit admission)

9. Operative procedures (e.g. hysterectomy, uterine compression sutures)

10. Organ failure

11. Intensive care unit admission

12. Maternal death

13. Maternal satisfaction

14. Caregiver satisfaction

15. Measures of cost‐effectiveness as defined by trial authors

16. Evacuation of retained products

17. Infection

18. Maternal pain (non‐prespecified outcome)

19. Cord rupture (non‐prespecified outcome)

20. Uterine inversion (non‐prespecified outcome)

(1) Sequence generation (checking for possible selection bias)

We described for each included study the method used to generate the allocation sequence in sufficient detail to allow an assessment of whether it should produce comparable groups.

We assessed the method as:

• low risk of bias (any truly random process, e.g. random number table; computer random number generator);

• high risk of bias (any non‐random process, e.g. odd or even date of birth; hospital or clinic record number);

• unclear risk of bias.

(2) Allocation concealment (checking for possible selection bias)

We described for each included study the method used to conceal allocation to interventions prior to assignment and assessed whether intervention allocation could have been foreseen in advance of, or during recruitment, or changed after assignment.

We assessed the methods as:

• low risk of bias (e.g. telephone or central randomisation; consecutively numbered sealed opaque envelopes);

• high risk of bias (open random allocation; unsealed or non‐opaque envelopes, alternation; date of birth);

• unclear risk of bias.

(3.1) Blinding of participants and personnel (checking for possible performance bias)

We described for each included study the methods used, if any, to blind study participants and personnel from knowledge of which intervention a participant received. We considered that studies were at low risk of bias if they were blinded, or if we judged that the lack of blinding would be unlikely to affect results. We planned to assess blinding separately for different outcomes or classes of outcomes.

We assessed the methods as:

• low, high or unclear risk of bias for participants;

• low, high or unclear risk of bias for personnel.

(3.2) Blinding of outcome assessment (checking for possible detection bias)

We described for each included study the methods used, if any, to blind outcome assessors from knowledge of which intervention a participant received. We planned to assess blinding separately for different outcomes or classes of outcomes.

We assessed methods used to blind outcome assessment as:

• low, high or unclear risk of bias.

(4) Incomplete outcome data (checking for possible attrition bias due to the amount, nature and handling of incomplete outcome data)

We described for each included study, and for each outcome or class of outcomes, the completeness of data including attrition and exclusions from the analysis. We stated whether attrition and exclusions were reported and the numbers included in the analysis at each stage (compared with the total randomised participants), reasons for attrition or exclusion where reported, and whether missing data were balanced across groups or were related to outcomes. Where sufficient information was reported, or could be supplied by the trial authors, we planned to re‐include missing data in the analyses which we undertook.

We assessed methods as:

• low risk of bias (e.g. no missing outcome data; missing outcome data balanced across groups; or less than 20% losses to follow‐up);

• high risk of bias (e.g. numbers or reasons for missing data imbalanced across groups; ‘as treated’ analysis done with substantial departure of intervention received from that assigned at randomisation);

• unclear risk of bias.

(5) Selective reporting bias

We described for each included study how we investigated the possibility of selective outcome reporting bias and what we found. We assessed the methods as:

• low risk of bias (where it is clear that all of the study’s prespecified outcomes and all expected outcomes of interest to the review have been reported);

• high risk of bias (where not all the study’s prespecified outcomes have been reported; one or more reported primary outcomes were not prespecified; outcomes of interest are reported incompletely and so cannot be used; study fails to include results of a key outcome that would have been expected to have been reported);

• unclear risk of bias.

(6) Other sources of bias (checking for bias due to problems not covered by (1) to (5) above)

We described for each included study any important concerns we had about other possible sources of bias.

We assessed whether studies that included multiple pregnancies accounted appropriately for non‐independence of babies from the same pregnancy in the analysis. There are several ways this can be done, and these studies should present something like an odds ratio adjusted for non‐independence. If adjustment was not done, we assessed the potential for bias i.e. if multiples only made up a small proportion of the total then there is probably not much potential for bias.

We assessed whether each study was free of other problems that could put it at risk of bias:

• low risk of other bias;

• high risk of other bias;

• unclear whether there is risk of other bias.

(7) Overall risk of bias

We made explicit judgements about whether studies are at high risk of bias, according to the criteria given in the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2011). With reference to (1) to (6) above, we assessed the likely magnitude and direction of the bias and whether we consider it likely to impact on the findings. In future updates of this review, as more data become available we will explore the impact of the level of bias through undertaking sensitivity analyses (see Sensitivity analysis). 

Dichotomous data

For dichotomous data, we presented results as summary risk ratios (RRs) with 95% confidence intervals (CIs). 

Continuous data

For continuous data, we used the mean difference (MD) if outcomes are measured in the same way between trials. In future updates, if appropriate, we will use the standardised MD to combine trials that measure the same outcome, but use different methods.  

Cluster‐randomised trials

In future updates, if cluster‐randomised trials are identified for inclusion, we will include cluster‐randomised trials in the analyses along with individually randomised trials. We will adjust their sample using the methods described in the Cochrane Handbook for Systematic Reviews of Interventions using an estimate of the intracluster correlation co‐efficient (ICC) derived from the trial (if possible), from a similar trial or from a study of a similar population (Higgins 2011). If we use ICCs from other sources, we will report this and conduct sensitivity analyses to investigate the effect of variation in the ICC. If we identify both cluster‐randomised trials and individually randomised trials, we plan to synthesise the relevant information. We will consider it reasonable to combine the results from both if there is little heterogeneity between the study designs and the interaction between the effect of intervention and the choice of randomisation unit is considered to be unlikely.

We will also acknowledge heterogeneity in the randomisation unit and perform a subgroup analysis to investigate the effects of the randomisation unit.