A randomized clinical trial comparing oral misoprostol with synthetic oxytocin or syntometrine in the third stage of labour

Uterotonic drugs to prevent postpartum haemorrhage: a network meta-analysis

BACKGROUND

Postpartum haemorrhage (PPH) is the leading cause of maternal mortality worldwide. Prophylactic uterotonic drugs can reduce blood loss and are routinely recommended. There are several uterotonic drugs for preventing PPH, but it is still debatable which drug or combination of drugs is the most effective.

OBJECTIVES

To identify the most effective and cost-effective uterotonic drug(s) to prevent PPH, and generate a ranking according to their effectiveness and side-effect profile.

METHODS

The Cochrane Pregnancy and Childbirth's Trials Register (1 June 2015), ClinicalTrials.gov and the World Health Organization (WHO)'s International Clinical Trials Registry Platform (ICTRP) were searched for unpublished trial reports (30 June 2015). In addition, reference lists of retrieved studies (updated October 2017) were searched for randomised trials evaluating uterotonic drugs for preventing PPH. The study estimated relative effects and rankings for preventing PPH, defined as blood loss of ≥ 500 ml and ≥ 1000 ml. Pairwise meta-analyses and network meta-analysis were performed to determine the relative effects and rankings of all available drugs and combinations thereof [ergometrine, misoprostol (Cytotec^®; Pfizer Inc., New York, NY, USA), misoprostol plus oxytocin (Syntocinon^®; Novartis International AG, Basel, Switzerland), carbetocin (Pabal^®; Ferring Pharmaceuticals, Saint-Prex, Switzerland), ergometrine plus oxytocin (Syntometrine^®; Alliance Pharma plc, Chippenham, UK), oxytocin, and a placebo or no treatment]. Primary outcomes were stratified according to the mode of birth, prior risk of PPH, health-care setting, drug dosage, regimen and route of drug administration. Sensitivity analyses were performed according to study quality and funding source, among others. A model-based economic evaluation compared the relative cost-effectiveness separately for vaginal births and caesareans with or without including side effects.

RESULTS

From 137 randomised trials and 87,466 women, ergometrine plus oxytocin, carbetocin and misoprostol plus oxytocin were found to reduce the risk of PPH blood loss of ≥ 500 ml compared with the standard drug, oxytocin [ergometrine plus oxytocin: risk ratio (RR) 0.69, 95% confidence interval (CI) 0.57 to 0.83; carbetocin: RR 0.72, 95% CI 0.52 to 1.00; misoprostol plus oxytocin: RR 0.73, 95% CI 0.6 to 0.9]. Each of these three strategies had 100% cumulative probability of being ranked first, second or third most effective. Oxytocin was ranked fourth, with an almost 0% cumulative probability of being ranked in the top three. Similar rankings were noted for the reduction of PPH blood loss of ≥ 1000 ml (ergometrine plus oxytocin: RR 0.77, 95% CI 0.61 to 0.95; carbetocin: RR 0.70, 95% CI 0.38 to 1.28; misoprostol plus oxytocin: RR 0.90, 95% CI 0.72 to 1.14), and most secondary outcomes. Ergometrine plus oxytocin and misoprostol plus oxytocin had the poorest ranking for side effects. Carbetocin had a favourable side-effect profile, which was similar to oxytocin. However, the analysis was restricted to high-quality studies, carbetocin lost its ranking and was comparable to oxytocin. The relative cost-effectiveness of the alternative strategies is inconclusive, and the results are affected by both the uncertainty and inconsistency in the data reported on adverse events. For vaginal delivery, when assuming no adverse events, ergometrine plus oxytocin is less costly and more effective than all strategies except carbetocin. The strategy of carbetocin is both more effective and more costly than all other strategies. When taking adverse events into consideration, all prevention strategies, except oxytocin, are more costly and less effective than carbetocin. For delivery by caesarean section, with and without adverse events, the relative cost-effectiveness is different, again because of the uncertainty in the available data.

LIMITATIONS

There was considerable uncertainty in findings within the planned subgroup analyses, and subgroup effects cannot be ruled out.

CONCLUSIONS

Ergometrine plus oxytocin, carbetocin and misoprostol plus oxytocin are more effective uterotonic drug strategies for preventing PPH than the current standard, oxytocin. Ergometrine plus oxytocin and misoprostol plus oxytocin cause significant side effects. Carbetocin has a favourable side-effect profile, which was similar to oxytocin. However, most carbetocin trials are small and of poor quality. There is a need for a large high-quality trial comparing carbetocin with oxytocin; such a trial is currently being conducted by the WHO. The relative cost-effectiveness is inconclusive, and results are affected by uncertainty and inconsistency in adverse events data.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42015020005; Cochrane Pregnancy and Childbirth Group (substudy) reference number 0871; PROSPERO-Cochrane (substudy) reference number CRD42015026568; and sponsor reference number ERN_13-1414 (University of Birmingham, Birmingham, UK).

FUNDING

Funding for this study was provided by the National Institute for Health Research Health Technology Assessment programme in a research award to the University of Birmingham and supported by the UK charity Ammalife (UK-registered charity 1120236). The funders of the study had no role in study design, data collection, data synthesis, interpretation or writing of the report.

Uterotonic agents for preventing postpartum haemorrhage: a network meta-analysis

BACKGROUND

Postpartum haemorrhage (PPH) is the leading cause of maternal mortality worldwide. Prophylactic uterotonic agents can prevent PPH, and are routinely recommended. The current World Health Organization (WHO) recommendation for preventing PPH is 10 IU (international units) of intramuscular or intravenous oxytocin. There are several uterotonic agents for preventing PPH but there is still uncertainty about which agent is most effective with the least side effects. This is an update of a Cochrane Review which was first published in April 2018 and was updated to incorporate results from a recent large WHO trial.

OBJECTIVES

To identify the most effective uterotonic agent(s) to prevent PPH with the least side effects, and generate a ranking according to their effectiveness and side-effect profile.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (24 May 2018), and reference lists of retrieved studies.

SELECTION CRITERIA

All randomised controlled trials or cluster-randomised trials comparing the effectiveness and side effects of uterotonic agents with other uterotonic agents, placebo or no treatment for preventing PPH were eligible for inclusion. Quasi-randomised trials were excluded. Randomised trials published only as abstracts were eligible if sufficient information could be retrieved.

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. Secondary outcomes included blood loss and related outcomes, morbidity outcomes, maternal well-being and satisfaction and side effects. Primary outcomes were also reported for pre-specified subgroups, stratifying by mode of birth, prior risk of PPH, healthcare setting, dosage, regimen and route of administration. We performed pairwise meta-analyses and network meta-analysis to determine the relative effects and rankings of all available agents.

MAIN RESULTS

The network meta-analysis included 196 trials (135,559 women) involving seven uterotonic agents and placebo or no treatment, conducted across 53 countries (including high-, middle- and low-income countries). Most trials were performed in a hospital setting (187/196, 95.4%) with women undergoing a vaginal birth (71.5%, 140/196).Relative effects from the network meta-analysis suggested that all agents were effective for preventing PPH ≥ 500 mL when compared with placebo or no treatment. The three highest ranked uterotonic agents for prevention of PPH ≥ 500 mL were ergometrine plus oxytocin combination, misoprostol plus oxytocin combination and carbetocin. There is evidence that ergometrine plus oxytocin (RR 0.70, 95% CI 0.59 to 0.84, moderate certainty), carbetocin (RR 0.72, 95% CI 0.56 to 0.93, moderate certainty) and misoprostol plus oxytocin (RR 0.70, 95% CI 0.58 to 0.86, low certainty) may reduce PPH ≥ 500 mL compared with oxytocin. Low-certainty evidence suggests that misoprostol, injectable prostaglandins, and ergometrine may make little or no difference to this outcome compared with oxytocin.All agents except ergometrine and injectable prostaglandins were effective for preventing PPH ≥ 1000 mL when compared with placebo or no treatment. High-certainty evidence suggests that ergometrine plus oxytocin (RR 0.83, 95% CI 0.66 to 1.03) and misoprostol plus oxytocin (RR 0.88, 95% CI 0.70 to 1.11) make little or no difference in the outcome of PPH ≥ 1000 mL compared with oxytocin. Low-certainty evidence suggests that ergometrine may make little or no difference to this outcome compared with oxytocin meanwhile the evidence on carbetocin was of very low certainty. High-certainty evidence suggests that misoprostol is less effective in preventing PPH ≥ 1000 mL when compared with oxytocin (RR 1.19, 95% CI 1.01 to 1.42). Despite the comparable relative treatment effects between all uterotonics (except misoprostol) and oxytocin, ergometrine plus oxytocin, misoprostol plus oxytocin combinations and carbetocin were the highest ranked agents for PPH ≥ 1000 mL.Misoprostol plus oxytocin reduces the use of additional uterotonics (RR 0.56, 95% CI 0.42 to 0.73, high certainty) and probably also reduces the risk of blood transfusion (RR 0.51, 95% CI 0.37 to 0.70, moderate certainty) when compared with oxytocin. Carbetocin, injectable prostaglandins and ergometrine plus oxytocin may also reduce the use of additional uterotonics but the certainty of the evidence is low. No meaningful differences could be detected between all agents for maternal deaths or severe morbidity as these outcomes were rare in the included randomised trials where they were reported.The two combination regimens were associated with important side effects. When compared with oxytocin, misoprostol plus oxytocin combination increases the likelihood of vomiting (RR 2.11, 95% CI 1.39 to 3.18, high certainty) and fever (RR 3.14, 95% CI 2.20 to 4.49, moderate certainty). Ergometrine plus oxytocin increases the likelihood of vomiting (RR 2.93, 95% CI 2.08 to 4.13, moderate certainty) and may make little or no difference to the risk of hypertension, however absolute effects varied considerably and the certainty of the evidence was low for this outcome.Subgroup analyses did not reveal important subgroup differences by mode of birth (caesarean versus vaginal birth), setting (hospital versus community), risk of PPH (high versus low risk for PPH), dose of misoprostol (≥ 600 mcg versus < 600 mcg) and regimen of oxytocin (bolus versus bolus plus infusion versus infusion only).

AUTHORS' CONCLUSIONS

All agents were generally effective for preventing PPH when compared with placebo or no treatment. Ergometrine plus oxytocin combination, carbetocin, and misoprostol plus oxytocin combination may have some additional desirable effects compared with the current standard oxytocin. The two combination regimens, however, are associated with significant side effects. Carbetocin may be more effective than oxytocin for some outcomes without an increase in side effects.

Uterotonic agents for preventing postpartum haemorrhage: a network meta-analysis

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.

Misoprostol versus ergometrine-oxytocin for preventing postpartum haemorrhage: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

To compare the effects of misoprostol versus ergometrine-oxytocin for postpartum haemorrhage (PPH) prevention, and provide important evidence to choose optimal agents for preventing PPH in developing countries.

METHODS

The Cochrane Central Register of Controlled Trials, PubMed, EMbase, and ClinicalTrails.gov were searched from inception to 1st January 2016. Two authors independently extracted data and assessed risk of bias of studies according to Cochrane Handbook5.1.0. Meta-analysis was performed using RevMan5.2.4 software.

RESULTS

A total of 4034 women from six randomized controlled trials (RCTs) were included. Meta-analyses showed that the PPH rate (7.6% vs. 4.2%, RR = 1.81, 95%CI (1.40, 2.35), P < 0.01), and the additional uterotonic therapy (19.2% vs. 10.5%, RR = 1.83, 95%CI (1.57, 2.14), P < 0.01) for misoprostol group were significantly higher than ergometrine-oxytocin group, respectively. But there was no significant difference of severe PPH rate between two groups (1.2% vs. 0.76%, RR = 1.55, 95%CI (0.78, 3.07), P = 0.21). The need for manual removal of placenta in misoprostol was only about one-third of ergometrine-oxytocin (0.5% vs. 1.4%, RR = 0.33, 95%CI (0.15, 0.76), P < 0.01).

CONCLUSIONS

Misoprostol can be used in the third stage of labor for preventing PPH where sterilized syringe and trained midwife were absent, and ergoetrine-oxytocin could be deemed as alternative agent in low-resource setting due to recognized effect. As a result of limited evidence about these uterotonic agents, the more high-quality RCTs are needed to determine the potentials and harms of various uterotonic agents for preventing PPH in developing countries.

Postpartum misoprostol for preventing maternal mortality and morbidity

BACKGROUND

The primary objective of postpartum haemorrhage (PPH) prevention and treatment is to reduce maternal deaths. Misoprostol has the major public health advantage over injectable medication that it can more easily be distributed at community level. Because misoprostol might have adverse effects unrelated to blood loss which might impact on mortality or severe morbidity, it is important to continue surveillance of all relevant evidence from randomised trials. This is particularly important as misoprostol is being introduced on a large scale for PPH prevention in low-income countries, and is commonly used for PPH treatment in well-resourced settings as well.

OBJECTIVES

To review maternal deaths and severe morbidity in all randomised trials of misoprostol for prevention or treatment of PPH.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (11 January 2013).

SELECTION CRITERIA

We included randomised trials including pregnant women who received misoprostol in the postpartum period, versus placebo/no treatment or other uterotonics for prevention or treatment of PPH, and reporting on maternal death, severe morbidity or pyrexia.We planned to include cluster- and quasi-randomised trials in the analysis, as a very large number of women will be needed to obtain robust estimates of maternal mortality but we did not identify any for this version of the review. In future updates of this review we will include trials reported only as abstracts if sufficient information is available from the abstract or from the authors.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and extracted data.

MAIN RESULTS

We included 78 studies (59,216 women) and excluded 34 studies.There was no statistically significant difference in maternal mortality for misoprostol compared with control groups overall (31 studies; 11/19,715 versus 4/20,076 deaths; risk ratio (RR) 2.08, 95% confidence interval (CI) 0.82 to 5.28); or for the trials of misoprostol versus placebo: 10 studies, 6/4626 versus 1/4707 ; RR 2.70; 95% CI 0.72 to 10.11; or for misoprostol versus other uterotonics: 21 studies, 5/15,089 versus 3/15,369 (19/100,000); RR 1.54; 95% CI 0.40 to 5.92. All 11 deaths in the misoprostol arms occurred in studies of misoprostol ≥ 600 µg.There was a statistically significant difference in the composite outcome 'maternal death or severe morbidity' for the comparison of misoprostol versus placebo (12 studies; average RR 1.70, 95% CI 1.02 to 2.81; Tau² = 0.00, I² = 0%) but not for the comparison of misoprostol versus other uterotonics (17 studies; average RR 1.50, 95% CI 0.50 to 4.52; Tau² = 1.81, I² = 69%). When we excluded hyperpyrexia from the composite outcome in exploratory analyses, there was no significant difference in either of these comparisons.Pyrexia > 38°C was increased with misoprostol compared with controls (56 studies, 2776/25,647 (10.8%) versus 614/26,800 (2.3%); average RR 3.97, 95% CI 3.13 to 5.04; Tau² = 0.47, I² = 80%). The effect was greater for trials using misoprostol 600 µg or more (27 studies; 2197/17,864 (12.3%) versus 422/18,161 (2.3%); average RR 4.64; 95% CI 3.33 to 6.46; Tau² = 0.51, I² = 86%) than for those using misoprostol 400 µg or less (31 studies; 525/6751 (7.8%) versus 185/7668 (2.4%); average RR 3.07; 95% CI 2.25 to 4.18; Tau² = 0.29, I² = 58%).

AUTHORS' CONCLUSIONS

Misoprostol does not appear to increase or reduce severe morbidity (excluding hyperpyrexia) when used to prevent or treat PPH. Misoprostol did not increase or decrease maternal mortality. However, misoprostol is associated with an increased risk of pyrexia, particularly in dosages of 600 µg or more. Given that misoprostol is used prophylactically in very large numbers of healthy women, the greatest emphasis should be placed on limiting adverse effects. In this context, the findings of this review support the use of the lowest effective dose. As for any new medication being used on a large scale, continued vigilance for adverse effects is essential and there is a need for large randomised trials to further elucidate both the relative effectiveness and the risks of various dosages of misoprostol.

Misoprostol for prevention and treatment of postpartum haemorrhage: A systematic review

Background: Postpartum haemorrhage (PPH) is a leading cause of maternal mortality especially in the developing world. Misoprostol, a highly effective drug is highly effective in inducing uterine contractions and has been proposed as a low-cost, easy-to-use intervention for PPH.Objective: This study assessed evidence of the effectiveness of misoprostol for the prevention and treatment of PPH.Method: Databases searched included MEDLINE, PUBMED, CINHAL, Google Scholar, Cochrane Central Register of Controlled Trials (CENTRAL) and EMBASE. Reference lists and conference proceedings were also searched for more studies. Three studies included in the meta-analysis were limited to randomised controlled trials (RCT). Two reviewers independently screened all articles for methodological quality using a standardised instrument adapted from the Cochrane Collaboration website. Data were entered in Review Manager 5.1 software for analysis.Results: Three trials (n = 2346) compared misoprostol to a placebo. Misoprostol was shown not to be effective in reducing PPH (risk ratios [RR] 0.65; 95% confidence interval [CI] 0.40–1.06). Only one trial reported on the need for a blood transfusion (RR 0.14; 95% CI 0.02–1.15). Shivering (RR 2.75; 95% CI 2.26–3.34) and pyrexia (RR 5.34; 95% CI 2.86–9.96) were significantly more common with misoprostol than with a placebo.Conclusion: The use of misoprostol was not associated with any significant reduction in the incidence of PPH. Therefore, in order to verify the efficacious use of misoprostol in the treatment of PPH, specialised investigations of its dose and routes of administration for clinically significant effects and acceptable side effects are warranted.

Prostaglandins for preventing postpartum haemorrhage

BACKGROUND

Prostaglandins have mainly been used for postpartum haemorrhage (PPH) when other measures fail. Misoprostol, a new and inexpensive prostaglandin E1 analogue, has been suggested as an alternative for routine management of the third stage of labour.

OBJECTIVES

To assess the effects of prophylactic prostaglandin use in the third stage of labour.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (7 January 2011). We updated this search on 25 May 2012 and added the results to the awaiting classification section.

SELECTION CRITERIA

Randomised trials comparing a prostaglandin agent with another uterotonic or no prophylactic uterotonic (nothing or placebo) as part of management of the third stage of labour. The primary outcomes were blood loss 1000 mL or more and the use of additional uterotonics.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed eligibility and trial quality and extracted data.

MAIN RESULTS

We included 72 trials (52,678 women). Oral or sublingual misoprostol compared with placebo is effective in reducing severe PPH (oral: seven trials, 6225 women, not totalled due to significant heterogeneity; sublingual: risk ratio (RR) 0.66; 95% confidence interval (CI) 0.45 to 0.98; one trial, 661 women) and blood transfusion (oral: RR 0.31; 95% CI 0.10 to 0.94; four trials, 3519 women).Compared with conventional injectable uterotonics, oral misoprostol was associated with higher risk of severe PPH (RR 1.33; 95% CI 1.16 to 1.52; 17 trials, 29,797 women) and use of additional uterotonics, but with a trend to fewer blood transfusions (RR 0.84; 95% CI 0.66 to 1.06; 15 trials; 28,213 women). Additional uterotonic data were not totalled due to heterogeneity. Misoprostol use is associated with significant increases in shivering and a temperature of 38º Celsius compared with both placebo and other uterotonics.

AUTHORS' CONCLUSIONS

Oral or sublingual misoprostol shows promising results when compared with placebo in reducing blood loss after delivery. The margin of benefit may be affected by whether other components of the management of the third stage of labour are used or not. As side-effects are dose-related, research should be directed towards establishing the lowest effective dose for routine use, and the optimal route of administration.Neither intramuscular prostaglandins nor misoprostol are preferable to conventional injectable uterotonics as part of the management of the third stage of labour especially for low-risk women; however, evidence has been building for the use of oral misoprostol to be effective and safe in areas with low access to facilities and skilled healthcare providers and future research on misoprostol use in the community should focus on implementation issues.

Management of third stage of labor with misoprostol: A comparison of three routes of administration

BACKGROUND AND CONTEXT

Misoprostol is a versatile drug with an effective uterotonic effect on the postpartum uterine tissue and is used through various routes during the third stage of labor.

AIMS AND OBJECTIVES

A randomized prospective study was carried out to analyze the most effective route for misoprostol administration, with an emphasis on parturients' acceptability and compliance, a possible shortening of the duration of the third stage of labor, minimization of blood loss and possibly reducing the incidence of potential side effects.

MATERIALS AND METHODS

The study groups comprised of 300 healthy parturients, divided randomly into three groups of 100 parturients each, who were administered misoprostol 400 μg through the oral (O), rectal (R), and sublingual (S) routes, respectively, during the third stage of labor. Estimation of blood loss was measured in terms of fall in hemoglobin, hematocrit, and packed cell volume (PCV) levels, and duration of the third stage of labor was also compared.

RESULTS

The mean duration for the third stage of labor was significantly shorter in group S (3.62 minutes) as compared to R (4.12 minutes), and O (4.94 minutes) (P = 0.02). The average blood loss was observed to be the least in the group S (210 ml) as compared to group R (230 ml), and group O. The incidence of shivering and fever was observed to be significantly higher (25 and 15%) in the parturients of group S (P < 0.05).

CONCLUSIONS

All routes were equally effective in managing the third stage of labor, but administration of misoprostol through the rectal route evoked better acceptability, comparable efficacy, and had an incidence of minimal side effects.

Misoprostol for the prevention and treatment of postpartum hemorrhage

INTRODUCTION

Uterotonic drugs are recommended for the prevention and treatment of postpartum hemorrhage (PPH), and oxytocin is considered the gold standard for both indications due to its established efficacy and safety. Unfortunately, access to oxytocin is still limited in many low-resource settings due to the need for cool storage, sterile equipment and administration by skilled personnel. Misoprostol , an E1 prostaglandin analog, has therefore been explored as an alternative for such settings due to its proven ability to induce uterine contractions, low cost, stability at room temperature and ease of administration.

AREAS COVERED

This review covers evidence from 51 randomized controlled trials for both prevention and treatment of PPH. It discusses efficacy and side effects in the context of the various doses that have been studied using oral, sublingual or rectal routes of administration for both indications.

EXPERT OPINION

There is now a solid body of evidence to justify the use of misoprostol for postpartum hemorrhage indications in many settings. The evidence supports use of 600 μg orally for the prevention of PPH and 800 μg sublingually for the treatment of PPH. There is no evidence to support the adjunct use of misoprostol following administration of conventional uterotonics for prevention or treatment purposes.

Misoprostol to prevent and treat postpartum haemorrhage: a systematic review and meta-analysis of maternal deaths and dose-related effects

OBJECTIVE

To review maternal deaths and the dose-related effects of misoprostol on blood loss and pyrexia in randomized trials of misoprostol use for the prevention or treatment of postpartum haemorrhage.

METHODS

We searched the Cochrane Controlled Trials Register and Pubmed, without language restrictions, for '(misoprostol AND postpartum) OR (misoprostol AND haemorrhage) OR (misoprostol AND hemorrhage)', and we evaluated reports identified through the Cochrane Pregnancy and Childbirth Group search strategy. Randomized trials comparing misoprostol with either placebo or another uterotonic to prevent or treat postpartum haemorrhage were checked for eligibility. Data were extracted, tabulated and analysed with Reviewer Manager (RevMan) 4.3 software.

FINDINGS

We included 46 trials with more than 40,000 participants in the final analysis. Of 11 deaths reported in 5 trials, 8 occurred in women receiving >or= 600 microg of misoprostol (Peto odds ratio, OR: 2.49; 95% confidence interval, CI: 0.76-8.13). Severe morbidity, defined as the need for major surgery, admission to intensive care, organ failure or body temperature >or= 40 degrees C, was relatively infrequent. In prevention trials, severe morbidity was experienced by 16 of 10,281 women on misoprostol and by 16 of 10,292 women on conventional uterotonics; in treatment trials, it was experienced by 1 of 32 women on misoprostol and by 1 of 32 women on conventional uterotonics. Misoprostol recipients experienced more adverse events than placebo recipients: 8 of 2070 versus 5 of 2032, respectively, in prevention trials, and 5 of 196 versus 2 of 202, respectively, in treatment trials. Meta-analysis of direct and adjusted indirect comparisons of the results of randomized trials showed no evidence that 600 microg are more effective than 400 microg for preventing blood loss > 1000 ml (relative risk, RR: 1.02; 95% CI: 0.71-1.48). Pyrexia was more than twice as common among women who received > 600 microg rather than 400 microg of misoprostol (RR: 2.53; 95% CI: 1.78-3.60).

CONCLUSION

Further research is needed to more accurately assess the potential beneficial and harmful effects of misoprostol and to determine the smallest dose that is effective and safe. In this review, 400 microg of misoprostol were found to be safer than > 600 microg and just as effective.

Prostaglandins for preventing postpartum haemorrhage

BACKGROUND

Prostaglandins have mainly been used for postpartum haemorrhage (PPH) when other measures fail. Misoprostol, a new and inexpensive prostaglandin E1 analogue, has been suggested as an alternative for routine management of the third stage of labour.

OBJECTIVES

To assess the effects of prophylactic prostaglandin use in the third stage of labour.

SEARCH STRATEGY

The Cochrane Pregnancy and Childbirth Group's Trials Register (February 2007) and PubMed (July 2006).

SELECTION CRITERIA

Randomized trials comparing a prostaglandin agent with another uterotonic or no prophylactic uterotonic (nothing or placebo) as part of management of the third stage of labour. The primary outcomes were blood loss 1000 ml or more and the use of additional uterotonics.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed eligibility and trial quality and extracted data.

MAIN RESULTS

Thirty-seven misoprostol and nine intramuscular prostaglandin trials (42,621 women) were included. Oral (seven trials, 2849 women) or sublingual misoprostol (relative risk (RR) 0.66; 95% confidence interval (CI) 0.45 to 0.98; one trial, 661 women) compared to placebo may be effective in reducing severe PPH and blood transfusion (RR 0.31; 95% CI 0.10 to 0.94; five oral misoprostol trials, 3519 women). The severe PPH analysis of oral misoprostol trials was not totalled due to significant heterogeneity. Compared to conventional injectable uterotonics, oral misoprostol was associated with higher risk of severe PPH (RR 1.32; 95% CI 1.16 to 1.51; 16 trials, 29,042 women) and use of additional uterotonics but with fewer blood transfusions (RR 0.81; 95% CI 0.64 to 1.02; 15 trials, 27,858 women). Additional uterotonic data were not totalled due to heterogeneity. Misoprostol use is associated with significant increases in shivering and a temperature of 38 degrees Celsius. There are scarce data comparing injectable prostaglandins with the conventional injectable uterotonics on severe PPH and the use of additional uterotonics, the primary outcomes of this review.

AUTHORS' CONCLUSIONS

Misoprostol orally or sublingually at a dose of 600 mcg shows promising results when compared to placebo in reducing blood loss after delivery. The margin of benefit may be affected by whether other components of management of the third stage of labour are used or not. As side-effects are dose-related, research should be directed towards establishing the lowest effective dose for routine use, and the optimal route of administration. Neither intramuscular prostaglandins nor misoprostol are preferable to conventional injectable uterotonics as part of the management of the third stage of labour especially for low-risk women.

Misoprostol in preventing postpartum hemorrhage: A meta-analysis

OBJECTIVE

To assess misoprostol's ability to prevent postpartum hemorrhage (PPH) where no alternatives exist. Comparison to oxytocics demonstrates how similarly misoprostol achieves a level of effectiveness-obtainable only in hospitals-in remote locations around the world.

METHOD

Using the Mantel-Haenszel fixed-effects model and the DerSirmonian and Laird random-effects model, summary statistics indicated that misoprostol's excess risk of PPH was only 4% when compared to oxytocics.

RESULT

This risk difference was well within the range of expected results for all uterotonic agents and does not warrant branding misoprostol as an inferior drug.

CONCLUSION

Conventional uterotonic drugs should not be used to set the lowest-accepted level of effectiveness in settings where they are entirely unsuitable. Continuing to weigh the benefits of one effective drug against another only delays the distribution of misoprostol in countries where it is the only feasible choice and must be measured against no treatment at all.

Oral misoprostol in the third stage of labor

OBJECTIVE

To compare the efficacy of intravenous ergometrine, intramuscular oxytocin, and oral misoprostol in the control of postpartum hemorrhage.

METHODS

Mean blood loss, rates of blood loss between 500 and 1000 ml, hematocrit fall greater than 10%, and need for additional oxytocic agents and nature and rates of adverse effects were assessed in this prospective, randomized, controlled study.

RESULTS

All outcomes were similar in the 3 groups. The main adverse effects in the misoprostol group were temperatures higher than 99 degrees F, which normalized within 2 h and shivering, which was mild and self-limiting.

CONCLUSIONS

Oral misoprostol is as effective as conventional oxytocic agents in preventing postpartum hemorrhage and can be recommended for use in low-resource settings.

Third Stage of Labor

All staff involved in obstetric care should be competent in performing active management of the third stage of labor. Active management has been shown to be clearly superior to physiologic or expectant management. Comparison of the various uterotonic agents has pointed to misoprostol as a potential first-line agent in treating obstetric hemorrhage. Its cost, routes of delivery, and efficacy make it an appealing drug in urban and rural settings. By being facile with the active management of labor and the prompt recognition and treatment of postpartum hemorrhage, the morbidity from significant blood loss and subsequent surgery can be reduced significantly.

Buccal Misoprostol to Decrease Blood Loss After Vaginal Delivery: A Randomized Trial

OBJECTIVE

To assess the efficacy of buccal misoprostol to decrease bleeding after vaginal delivery.

METHODS

This was a randomized study of patients between 22 weeks and 42 weeks of gestation with anticipated vaginal delivery. Patients were given either a 200-mug misoprostol tablet or placebo in the buccal space at the time of cord clamping. A continuous dilute intravenous oxytocin infusion was given to all patients at delivery of the placenta. Postpartum hemorrhage was defined as blood loss exceeding 500 mL. Sample size calculations based on previous studies assumed a 13% incidence of postpartum hemorrhage in the control group. To show a statistically significant reduction of postpartum hemorrhage a total of 1,604 patients would be required in each group.

RESULTS

A total of 848 patients were enrolled and 756 randomly assigned, 377 in the misoprostol group and 379 in the placebo group. Demographic, antepartum, and intrapartum characteristics were similar between the groups. The incidence of postpartum hemorrhage, 3% compared with 5%, (relative risk 0.65, 95% confidence interval 0.33-1.29, P = .22), mean estimated blood loss, 322 compared with 329 mL, (P = .45), and mean minutes of the third stage of labor, 6.7 compared with 6.9 (P = .52) were similar between the groups, misoprostol and placebo, respectively. Hemoglobin difference before and after delivery, need for second or third uterotonic agent, and all measured neonatal variables including birth weights, and umbilical cord pH were similar between the groups.

CONCLUSION

Buccal misoprostol at cord clamping is no more effective than placebo in reducing postpartum hemorrhage.

Does the route of administration of misoprostol make a difference? The uterotonic effect and side effects of misoprostol given by different routes after vaginal delivery

OBJECTIVE

To compare the postpartum uterotonic effect and side effects of misoprostol administered by different routes.

STUDY DESIGN

Fifty women were given misoprostol 400 microg either by the oral solution, oral tablet, rectal or vaginal route, or intramuscular syntometrine 1 ml after spontaneous vaginal delivery. Pre- and post-treatment uterine activity were measured with intrauterine pressure catheters.

RESULTS

Uterine activity produced by oral solution misoprostol 400 microg was significantly higher than that of oral tablet, rectal and vaginal misoprostol (P = 0.004, 0.002, respectively). Onset of action after oral solution misoprostol was faster than by the oral tablet (P = 0.01), rectal (P < 0.001) and vaginal (P< 0.001) routes. Shivering and pyrexia were most common with oral solution misoprostol. Maximum body temperature recorded was significantly higher with oral solution misoprostol than with oral tablet, rectal and vaginal misoprostol (P = 0.009, 0.001, respectively).

CONCLUSION

Different routes of administering misoprostol greatly influence the effects achieved. Oral solution misoprostol produces the fastest and strongest uterotonic effect, with the most side effects.

Misoprostol: A Quarter Century of Use, Abuse, and Creative Misuse

Misoprostol is a prostaglandin E1 analog originally intended for use to prevent NSAID-induced gastric ulcers. However, because of its cervical ripening and uterotonic property, misoprostol has become one of the most useful drugs in obstetrics and gynecology. Misoprostol has proven to be a very convenient and flexible drug because of its formulation as a tablet that is stable and that can be administered orally, rectally, vaginally and by the sublingual route. Beginning with its abuse for illegal abortion in the late 1980s, misoprostol has quickly become established as one of the most effective drugs for terminating pregnancies in the first and second trimesters, as well as for inducing labor in the third trimester. Its use for routine prevention of postpartum hemorrhage has not been so successful, partly as the high doses required for this indication often result in troublesome side effects. Despite the large body of medical evidence about its efficacy and relative safety, the use of misoprostol in pregnant women remained off-label until the spring of 2002.

Prostaglandins for prevention of postpartum haemorrhage

BACKGROUND

Prostaglandins have mainly been used for postpartum haemorrhage when other measures fail. Misoprostol, a new and inexpensive prostaglandin E1 analogue, has been suggested as an alternative for routine management of the third stage of labour.

OBJECTIVES

To assess the effects of prophylactic prostaglandin use in the third stage of labour.

SEARCH STRATEGY

The Cochrane Pregnancy and Childbirth Group trials register (March 2003).

SELECTION CRITERIA

Randomized or quasi-randomized trials comparing a prostaglandin agent with another uterotonic or no prophylactic uterotonic (nothing or placebo) as part of management of the third stage of labour. There were no language preferences.

DATA COLLECTION AND ANALYSIS

Eligibility, trial quality and data extraction were done by two reviewers independently.

MAIN RESULTS

Twenty-four misoprostol and eight intramuscular prostaglandin trials (34,203 participants) were included. The data comparing oral misoprostol to no uterotonics/placebo are from five trials and difficult to interpret because of the heterogeneity between trials. However, the data do not suggest a substantive reduction in the rate of postpartum haemorrhage or other measures of blood loss. Oral misoprostol 600 mcg shows clinically and statistically significantly more blood loss = 1000 ml compared with conventional injectable uterotonics (seven trials, 22,749 women, 3.6% versus 2.7%; relative risk (RR) 1.34, 95% confidence interval (CI) 1.16 to 1.55). Shivering and elevated body temperature (> 38 masculine C) are the main side-effects of misoprostol and are dose related (600 mcg versus 400 mcg: shivering - two trials, RR: 1.33; 95% CI: 1.07 to 1.64). Compared to oxytocin the RR of any shivering with 600 mcg oral misoprostol is 3.29 (seven trials, 22746 women; 19.7% versus 6.0%, 95% CI 3.03 to 3.56) and temperature greater than 38 masculine C is RR 6.78 (seven trials, 22,09 women; 6.3% versus, 95% CI 5.55 to 8.30). Injectable prostaglandins are associated with reduced mean blood loss in the third stage of labour (weighted mean difference -70 ml, 95% CI -73 to -67 ml) when compared to conventional injectable uterotonics but have more side-effects. There are scarce data from this comparison on severe postpartum haemorrhage and the use of additional uterotonics, the primary outcomes of this review.

REVIEWER'S CONCLUSIONS

Neither intramuscular prostaglandins nor misoprostol are preferable to conventional injectable uterotonics as part of the active management of the third stage of labour especially for low-risk women. Future research on prostaglandin use after birth should focus on the treatment of postpartum haemorrhage rather than prevention where they seem to be more promising.

Prostaglandins in the prevention and management of postpartum haemorrhage

Myometrial contractility is integral to the delivery of the placenta and the arrest of potential subsequent haemorrhage. The details of this physiological process are patchy but it is clear that there is an important hormonal contribution. Oxytocin, with or without ergometrine, has thus been widely used with a recognized beneficial treatment effect. This practice, however, was never universal. The injectable nature of these agents restricted their wider use, even in societies with average medical services. The availability of the prostaglandin analogue misoprostol has renewed interest in the third stage of labour, has taken its pharmacological management to new frontiers, and has expanded the therapeutic options for the management of postpartum haemorrhage.

Misoprostol use during the third stage of labor

OBJECTIVES

To systematically review the efficacy of misoprostol compared with placebo or other uterotonics in preventing maternal morbidity associated with the third stage of labor.

METHODS

We identified, retrieved, evaluated, abstracted data, and assessed the quality of all published studies (from January 1996 to May 2002) which assessed misoprostol's efficacy in minimizing uterine blood loss during the third stage of labor. Seventeen studies included 28170 subjects; of these, approximately one-half received misoprostol with the remainder receiving either a placebo or another uterotonic agent. An estimate of the odds ratio (OR) and risk difference for dichotomous outcomes was calculated using a random- and fixed-effects model. Continuous outcomes were pooled using a variance-weighted average of within-study difference in means.

RESULTS

In assessing studies comparing misoprostol with placebo, those who received oral misoprostol had a decreased risk of needing additional uterotonics (OR 0.64, 95% confidence interval 0.46, 0.90). Compared with placebo, use of misoprostol was associated with an increased risk for shivering and pyrexia. In contrast, in studies comparing misoprostol with oxytocin, oxytocin was associated with significantly lower rates of postpartum hemorrhage, maternal shivering and pyrexia. In studies comparing misoprostol with Syntometrine, misoprostol was associated with higher rates of the need for additional uterotonic agent as well as shivering.

CONCLUSIONS

Misoprostol was inferior to oxytocin and other uterotonics with regard to any of the third stage of labor outcomes assessed. However, when compared to placebo, misoprostol had a decreased risk of needing additional uterotonics. Thus, in less-developed countries where administration of parenteral uterotonic drugs may be problematic, misoprostol represents a reasonable agent for the management of the third stage of labor. Additional randomized clinical trials examining objective outcome measures (i.e. need for blood transfusion or 10% hemoglobin change) may further define benefits and risks of misoprostol use during the third stage of labor.

Oral misoprostol for the third stage of labor: a randomized controlled trial

OBJECTIVE

To compare oral misoprostol with conventional oxytocics in the management of the third stage of labor. In a controlled trial, 1574 women were randomized into four groups, as follows: Group 1 received intravenous infusion of oxytocin 10 IU plus oral misoprostol 400 micro g, followed by two doses of oral misoprostol 100 micro g 4 hours apart; group 2 received oral misoprostol 400 micro g, followed by two doses of oral misoprostol 100 micro g 4 hours apart; group 3 received intravenous infusion of oxytocin 10 IU; and group 4 received intravenous infusion of oxytocin 10 IU plus intramuscular administration of methylergonovine maleate (Methergine) 0.2 mg. The incidence of postpartum hemorrhage and decrease in hemoglobin concentration from before delivery to 24 hours postpartum were the main outcome measures.

RESULTS

The primary outcome measures were similar in groups 2 and 3. The incidence of postpartum hemorrhage was 9% in group 2, compared with 3.2% in group 1 and 3.5% in group 4 (P <.01, and P =.01, respectively). There were no significant differences among the four groups regarding hemoglobin concentrations. Significantly more women needed additional oxytocin in group 2, when compared with group 4 (5.9% versus 2.2%; P =.01). The proportion of women requiring additional methylergonovine maleate was 4.8% in group 2, compared with 0.7% in group 1 and 1% in group 4 (P <.01 and P =.01, respectively).

CONCLUSION

Oral misoprostol alone is as effective as oxytocin alone for the prevention of postpartum hemorrhage; it is less effective than oxytocin plus methylergonovine maleate and oral misoprostol plus oxytocin.

Side effects of oral misoprostol during the first 24 hours after administration in the third stage of labour

OBJECTIVE

To evaluate the side effects of 600 microg misoprostol orally during the first 24 hours after administration in the third stage of labour.

DESIGN

Double blind randomised controlled trial.

SETTING

Tertiary care hospitals in Nigeria and Thailand.

SAMPLE

All women participating in the WHO Misoprostol trial in these two hospitals between January 1, 1999 and June 17, 1999.

METHODS

All women were followed up during the first 24 hours postpartum to evaluate the occurrence of shivering, nausea, vomiting, diarrhoea and other misoprostol-related side effects.

MAIN OUTCOME MEASURES

Rates of shivering, nausea, vomiting, diarrhoea and pyrexia within 1 hour and in the intervals 2-6, 7-12, 13-18 and 19-24 hours after delivery.

RESULTS

A total of 1686 women were enrolled. Women who received misoprostol had higher incidence than the oxytocin group of 'any' shivering in the first hour (RR 6.4, 95% CI 3.9 to 10.4) and the period covering 2-6 hours following delivery (RR 4.7, 95% CI 1.9 to 11.2). Pyrexia was also more common in the misoprostol group in both the same time intervals (RR 2.8, 95% CI 1.4 to 5.3 and RR 6.3, 95% CI 3.7 to 10.8, respectively). Diarrhoea was not present in the first hour in either group but appeared in the second time period (2-6 hours) and third time period (7-12 hours) more frequently in the misoprostol group than with oxytocin.

CONCLUSION

The increased incidence of shivering and pyrexia that occurs with postpartum use of misoprostol persists up to 6 hours following delivery. Approximately 5% of women experience diarrhoea that starts after 1 hour and subsides within 12 hours.

Use of the equivalence approach in reproductive health clinical trials

An equivalence trial is appropriate when it is desired to demonstrate equivalence between two treatments, regimens or interventions (methods) or non-inferiority of a new one compared to a standard one. The conduct of an equivalence trial requires different techniques during design and analysis compared to a superiority trial. The existing formulae for sample size calculation to demonstrate equivalence between two methods using the confidence interval approach are reviewed. The establishment of the margin of equivalence and the choice of the type of test are discussed. Plots of sample sizes required to demonstrate equivalence in the case of binary outcomes are presented for values of proportions and margins of equivalence common in the reproductive health field. Examples are given of method comparisons in the reproductive health field in which the relevant question is to demonstrate non-inferiority. The approach to equivalence is described in the trials included in three published systematic reviews in which these comparisons were conducted, addressing the statement of hypotheses, sample size calculation and the interpretation of results. The use of the conventional superiority approach to design equivalence trials has led to underpowered trials to show equivalence within clinical relevant margins. The analysis and interpretation of results from such trials has resulted in conclusions of equivalence based on lack of significance. We draw attention to the lack of awareness of the appropriate techniques for equivalence trials among researchers in the field of reproductive health. Finally, the issue of interim analyses and stopping rules in equivalence trials is addressed.

Misoprostol in the prevention of postpartum hemorrhage

OBJECTIVE

To evaluate the data regarding the use of misoprostol in the prevention of postpartum hemorrhage.

DATA SOURCES

Pertinent literature was identified through a MEDLINE search (1966-January 2001) and through other secondary literature databases and/or bibliographies of pertinent articles.

DATA SYNTHESIS

New strategies in the prevention of postpartum hemorrhage are being evaluated due to the obstacles surrounding conventional therapies. One therapeutic option is the use of misoprostol. This literature review evaluates the published clinical data involving misoprostol in the prevention of postpartum hemorrhage. Current data suggest that the use of misoprostol for the prevention of postpartum hemorrhage reduces mean estimated blood loss compared with placebo. However, no clinical trials have detected a statistically significant decrease in the incidence of postpartum hemorrhage in misoprostol-treated subjects. There is conflicting evidence regarding the efficacy of misoprostol compared with conventional uterotonics, such as oxytocin or Syntometrine.

CONCLUSIONS

In situations where conventional oxytocics are not readily available, storage requirements for oxytocics cannot be met, or the equipment for parenteral administration is not obtainable, misoprostol may be an acceptable prophylactic option.

Management of the third stage of labor: an evidence-based approach

The third stage of labor usually is eclipsed by the excitement of the birth of a baby. Evidence shows that management of this stage can directly influence important maternal outcomes such as blood loss, need for manual removal of the placenta, and postpartum hemorrhage. Most of the large trials have compared active management of the third stage to expectant management. Active management includes routine use of cord traction and uterotonins, whereas expectant management can be characterized as one of watchful waiting. The use of herbal therapies and homeopathic remedies lack study; additional factors such as site of birth and hydrotherapy also remain to be explored. However, on the basis of current evidence, if a decrease in postpartum bleeding or avoidance of manual removal is desired, an active approach to third stage is the one that should be adopted until and unless contradictory findings are published.

WHO multicentre randomised trial of misoprostol in the management of the third stage of labour

BACKGROUND

Postpartum haemorrhage is a leading cause of maternal morbidity and mortality. Active management of the third stage of labour, including use of a uterotonic agent, has been shown to reduce blood loss. Misoprostol (a prostaglandin E1 analogue) has been suggested for this purpose because it has strong uterotonic effects, can be given orally, is inexpensive, and does not need refrigeration for storage. We did a multicentre, double-blind, randomised controlled trial to determine whether oral misoprostol is as effective as oxytocin during the third stage of labour.

METHODS

In hospitals in Argentina, China, Egypt, Ireland, Nigeria, South Africa, Switzerland, Thailand, and Vietnam, we randomly assigned women about to deliver vaginally to receive 600 microg misoprostol orally or 10 IU oxytocin intravenously or intramuscularly, according to routine practice, plus corresponding identical placebos. The medications were administered immediately after delivery as part of the active management of the third stage of labour. The primary outcomes were measured postpartum blood loss of 1000 mL or more, and the use of additional uterotonics without an unacceptable level of side-effects. We chose an upper limit of a 35% increase in the risk of blood loss of 1000 mL or more as the margin of clinical equivalence, which was assessed by the confidence interval of the relative risk. Analysis was by intention to treat.

FINDINGS

9264 women were assigned misoprostol and 9266 oxytocin. 37 women in the misoprostol group and 34 in the oxytocin group had emergency caesarean sections and were excluded. 366 (4%) of women on misoprostol had a measured blood loss of 1000 mL or more, compared with 263 (3%) of those on oxytocin (relative risk 1.39 [95% CI 1.19-1.63], p<0.0001). 1398 (15%) women in the misoprostol group and 1002 (11%) in the oxytocin group required additional uterotonics (1.40 [1.29-1.51], p<0.0001). Misoprostol use was also associated with a significantly higher incidence of shivering (3.48 [3.15-3.84]) and raised body temperature (7.17 [5.67-9.07]) in the first hour after delivery.

INTERPRETATION

10 IU oxytocin (intravenous or intramuscular) is preferable to 600 microg oral misoprostol in the active management of the third stage of labour in hospital settings where active management is the norm.

Postpartum intrauterine pressure studies of the uterotonic effect of oral misoprostol and intramuscular syntometrine

OBJECTIVES

To investigate the effect of oral misoprostol in dosages varying from 200 microg to 800 microg on postpartum uterine contractility and to establish their side effects.

DESIGN

A prospective descriptive study.

PARTICIPANTS

Fifty-seven women who delivered vaginally after spontaneous labours not requiring augmentation.

METHODS

Within 5 minutes of delivery of the placenta, a calibrated Gaeltec catheter with an intrauterine pressure transducer at its tip was inserted transcervically into the uterine cavity. Cumulative uterine activity was recorded for 30 minutes in each woman before administering the oral misoprostol tablets and continued for a further 90 minutes after its administration. Thus each woman acted as her own control regarding changes in uterine contractility. Uterine activity was recorded on a Sonicaid Meridian fetal monitor, which measures active contraction area automatically. The incidence of side effects was also recorded.

RESULTS

There was no statistical difference (P = 0.887) in the adjusted mean difference in cumulative uterine activity following all the doses of oral misoprostol, compared with intramuscular syntometrine, the largest difference being seen in oral misoprostol 200 microg (adjusted mean difference -2282 kPas s, 95% CI -7954 to 3390 kPas s). The mean onset of action of oral misoprostol (6.1, SD 2.1 min) was significantly slower than that of intramuscular syntometrine (3.2, SD 1.5 min; P = 0.002), but their durations of action were similar (P = 0.637). In the misoprostol group the commonest side effects were shivering (36%) and a rise in body temperature above 38 degrees C (40%). In the syntometrine group, the most commonly observed side effect was moderate uterine pain (nine out of ten women) and a rise in diastolic blood pressure of 20 mmHg (two out of ten women).

CONCLUSION

The results of this study show that oral misoprostol has a definite uterotonic effect on the postpartum uterus. At doses of 200 microg to 400 microg, oral misoprostol has a similar uterotonic effect to intramuscular syntometrine. Higher doses of oral misoprostol are associated with significantly more side effects.