Background: Postpartum haemorrhage (PPH) is the leading cause of maternal mortality worldwide. Prophylactic uterotonic drugs can prevent PPH, and are routinely recommended. There are several uterotonic drugs for preventing PPH but it is still debatable which drug is best.
Objectives: To identify the most effective uterotonic drug(s) to prevent PPH, and generate a ranking according to their effectiveness and side-effect profile.
Search methods: We searched Cochrane Pregnancy and Childbirth''s Trials Register (1 June 2015), ClinicalTrials.gov and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) for unpublished trial reports (30 June 2015) and reference lists of retrieved studies.
Selection criteria: All randomised controlled comparisons or cluster trials of effectiveness or side-effects of uterotonic drugs for preventing PPH.Quasi-randomised trials and cross-over trials are not eligible for inclusion in this review.
Data collection and analysis: At least three review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy. We estimated the relative effects and rankings for preventing PPH ≥ 500 mL and PPH ≥ 1000 mL as primary outcomes. We performed pairwise meta-analyses and network meta-analysis to determine the relative effects and rankings of all available drugs. We stratified our primary outcomes according to mode of birth, prior risk of PPH, healthcare setting, dosage, regimen and route of drug administration, to detect subgroup effects.The absolute risks in the oxytocin are based on meta-analyses of proportions from the studies included in this review and the risks in the intervention groups were based on the assumed risk in the oxytocin group and the relative effects of the interventions.
Main results: This network meta-analysis included 140 randomised trials with data from 88,947 women. There are two large ongoing studies. The trials were mostly carried out in hospital settings and recruited women who were predominantly more than 37 weeks of gestation having a vaginal birth. The majority of trials were assessed to have uncertain risk of bias due to poor reporting of study design. This primarily impacted on our confidence in comparisons involving carbetocin trials more than other uterotonics.The three most effective drugs for prevention of PPH ≥ 500 mL were ergometrine plus oxytocin combination, carbetocin, and misoprostol plus oxytocin combination. These three options were more effective at preventing PPH ≥ 500 mL compared with oxytocin, the drug currently recommended by the WHO (ergometrine plus oxytocin risk ratio (RR) 0.69 (95% confidence interval (CI) 0.57 to 0.83), moderate-quality evidence; carbetocin RR 0.72 (95% CI 0.52 to 1.00), very low-quality evidence; misoprostol plus oxytocin RR 0.73 (95% CI 0.60 to 0.90), moderate-quality evidence). Based on these results, about 10.5% women given oxytocin would experience a PPH of ≥ 500 mL compared with 7.2% given ergometrine plus oxytocin combination, 7.6% given carbetocin, and 7.7% given misoprostol plus oxytocin. Oxytocin was ranked fourth with close to 0% cumulative probability of being ranked in the top three for PPH ≥ 500 mL.The outcomes and rankings for the outcome of PPH ≥ 1000 mL were similar to those of PPH ≥ 500 mL. with the evidence for ergometrine plus oxytocin combination being more effective than oxytocin (RR 0.77 (95% CI 0.61 to 0.95), high-quality evidence) being more certain than that for carbetocin (RR 0.70 (95% CI 0.38 to 1.28), low-quality evidence), or misoprostol plus oxytocin combination (RR 0.90 (95% CI 0.72 to 1.14), moderate-quality evidence)There were no meaningful differences between all drugs for maternal deaths or severe morbidity as these outcomes were so rare in the included randomised trials.Two combination regimens had the poorest rankings for side-effects. Specifically, the ergometrine plus oxytocin combination had the higher risk for vomiting (RR 3.10 (95% CI 2.11 to 4.56), high-quality evidence; 1.9% versus 0.6%) and hypertension [RR 1.77 (95% CI 0.55 to 5.66), low-quality evidence; 1.2% versus 0.7%), while the misoprostol plus oxytocin combination had the higher risk for fever (RR 3.18 (95% CI 2.22 to 4.55), moderate-quality evidence; 11.4% versus 3.6%) when compared with oxytocin. Carbetocin had similar risk for side-effects compared with oxytocin although the quality evidence was very low for vomiting and for fever, and was low for hypertension.
Authors' conclusions: Ergometrine plus oxytocin combination, carbetocin, and misoprostol plus oxytocin combination were more effective for preventing PPH ≥ 500 mL than the current standard oxytocin. Ergometrine plus oxytocin combination was more effective for preventing PPH ≥ 1000 mL than oxytocin. Misoprostol plus oxytocin combination evidence is less consistent and may relate to different routes and doses of misoprostol used in the studies. Carbetocin had the most favourable side-effect profile amongst the top three options; however, most carbetocin trials were small and at high risk of bias.Amongst the 11 ongoing studies listed in this review there are two key studies that will inform a future update of this review. The first is a WHO-led multi-centre study comparing the effectiveness of a room temperature stable carbetocin versus oxytocin (administered intramuscularly) for preventing PPH in women having a vaginal birth. The trial includes around 30,000 women from 10 countries. The other is a UK-based trial recruiting more than 6000 women to a three-arm trial comparing carbetocin, oxytocin and ergometrine plus oxytocin combination. Both trials are expected to report in 2018.Consultation with our consumer group demonstrated the need for more research into PPH outcomes identified as priorities for women and their families, such as women''s views regarding the drugs used, clinical signs of excessive blood loss, neonatal unit admissions and breastfeeding at discharge. To date, trials have rarely investigated these outcomes. Consumers also considered the side-effects of uterotonic drugs to be important but these were often not reported. A forthcoming set of core outcomes relating to PPH will identify outcomes to prioritise in trial reporting and will inform futures updates of this review. We urge all trialists to consider measuring these outcomes for each drug in all future randomised trials. Lastly, future evidence synthesis research could compare the effects of different dosages and routes of administration for the most effective drugs.
Ioannis D Gallos (IDG): is a co‐applicant to the UK National Institute for Health Research HTA Project Award 14/139/17 entitled “Uterotonic drugs for preventing postpartum haemorrhage: a network meta‐analysis and cost‐effectiveness analysis”. He has been involved in one or more previous or ongoing trials related to the use of uterotonics for the prevention of PPH that could be eligible for inclusion in this review. He will not participate in any decisions regarding these trials (i.e. assessment for inclusion/exclusion, trial quality, data extraction) for the purposes of this review or future updates – these tasks will be carried out by other members of the team who are not directly involved in the trials. Ferring Pharmaceuticals and Novartis have supplied carbetocin and oxytocin for studies and an ongoing study is supported by WHO/Merck for Mothers. IDG has been supported by the MSD for mothers initiative for travel to a meeting for the study.
Helen M Williams (HMW): is part‐funded by the Birmingham Women’s NHS Foundation Trust, and a co‐applicant to the UK National Institute for Health Research HTA Project Award 14/139/17 entitled “Uterotonic drugs for preventing postpartum haemorrhage: a network meta‐analysis and cost‐effectiveness analysis”. Her salary is part‐funded by Tommy''s. She is a member of the Executive Board of Ammalife (UK registered charity 1120236). She has also assisted the administration of activities at a single study site in contribution to a multinational randomised controlled trial of carbetocin versus oxytocin,that could potentially be eligible for inclusion in this review. The trial is sponsored by the World Health Organization and supported by Merck for Mothers. She will not participate in decisions regarding the inclusion of this trial in the review or any tasks related to it such as data extraction or quality assessment.
Malcolm J Price (MP) is funded as a research fellow by the UK Medical Research Council (MRC) Project Award MR/J013595/1, and a co‐applicant to the UK National Institute for Health Research HTA Project Award 14/139/17 entitled “Uterotonic drugs for preventing postpartum haemorrhage: a network meta‐analysis and cost‐effectiveness analysis”.
Aurelio Tobias: none known.
Abi Merriel (AM): was part‐funded by Ammalife (UK Registered Charity 1120236) and the Birmingham Women’s NHS Foundation Trust.
Harold Gee (HG): is a Trustee of Ammalife (UK Registered Charity 1120236).
David Lissauer (DL): was previously a Trustee of Ammalife (UK Registered Charity 1120236).
Vidhya Moorthy: none known.
Mariana Widmer (MW): is involved in an ongoing trial related to the use of uterotonics for the prevention of PPH that could be eligible for inclusion in this review. Ferring Pharmaceuticals and Novartis have supplied carbetocin and oxytocin for the trial and the study is supported by WHO/Merck for Mothers. MW will not participate in any decisions regarding this trial (i.e. assessment for inclusion/exclusion, trial quality, data extraction)for the purposes of this review or future updates – these tasks will be carried out by other members of the team who are not directly involved in the trial.
?zge Tun?alp (OT): is a co‐applicant to the UK National Institute for Health Research HTA Project Award 14/139/17 entitled “Uterotonic drugs for preventing postpartum haemorrhage: a network meta‐analysis and cost‐effectiveness analysis”.
A Metin Gulmezoglu (AMG): is a co‐applicant to the UK National Institute for Health Research HTA Project Award 14/139/17 entitled “Uterotonic drugs for preventing postpartum haemorrhage: a network meta‐analysis and cost‐effectiveness analysis”. AMG was involved in the large multicentre trial (as part of the central coordination unit) which may be included in the review. AMG is involved in an ongoing trial related to the use of uterotonics for the prevention of PPH that could be eligible for inclusion in this review. Ferring Pharmaceuticals and Novartis have supplied carbetocin and oxytocin for the trial and the study is supported by WHO/Merck for Mothers. AMG will not participate in any decisions regarding this or previous trials (i.e. assessment for inclusion/exclusion, trial quality, data extraction)for the purposes of this review or future updates – these tasks will be carried out by other members of the team who are not directly involved in the trial.
Jonathan J Deeks (JJD): is a co‐applicant to the UK National Institute for Health Research HTA Project Award 14/139/17 entitled “Uterotonic drugs for preventing postpartum haemorrhage: a network meta‐analysis and cost‐effectiveness analysis”.
G Justus Hofmeyr (GJH) has been and continues to be involved in a number of studies that may be eligible for inclusion in this review, but will not participate in data extraction or quality assessment of the studies in which he was involved. He is a co‐investigator on the UK National Institute for Health Research HTA Project Award 14/139/17 entitled "Uterotonic drugs for preventing postpartum haemorrhage: a network meta‐analysis and cost‐effectiveness analysis". Neither he nor his institution receives funding from this grant.
Arri Coomarasamy (AC): is the Chief Investigator of UK National Institute for Health Research HTA Project Award 14/139/17 entitled "Uterotonic drugs for preventing postpartum haemorrhage: a network meta‐analysis and cost‐effectiveness analysis". He has been involved in one or more previous or ongoing trials related to the use of uterotonics for the prevention of PPH that could be eligible for inclusion in this review. Ferring Pharmaceuticals and Novartis have supplied carbetocin and oxytocin for studies and an ongoing study is supported by WHO/Merck for Mothers. AC will not participate in any decisions regarding these trials (i.e. assessment for inclusion/exclusion, trial quality, data extraction)for the purposes of this review or future updates – these tasks will be carried out by other members of the team who are not directly involved in the trials. AC is a member of the Executive Board of Ammalife (UK registered charity 1120236). He does not receive any payment for this relationship.