Efficacy and safety of misoprostol compared with the dinoprostone for labor induction at term: a meta-analysis

Vaginal misoprostol versus vaginal dinoprostone for cervical ripening and induction of labour: An individual participant data meta-analysis of randomised controlled trials

BACKGROUND

Induction of labour (IOL) is common practice and different methods carry different effectiveness and safety profiles.

OBJECTIVES

To compare the effectiveness, and maternal and perinatal safety outcomes of IOL with vaginal misoprostol versus vaginal dinoprostone using individual participant data from randomised clinical trials.

SEARCH STRATEGY

The following databases were searched from inception to March 2023: CINAHL Plus, ClinicalTrials.gov, Cochrane Pregnancy and Childbirth Group Trial Register, Ovid Embase, Ovid Emcare, Ovid MEDLINE, Scopus and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP).

SELECTION CRITERIA

Randomised controlled trials (RCTs), with viable singleton gestation, no language restrictions, and all published and unpublished data.

DATA COLLECTION AND ANALYSIS

An individual participant data meta-analysis was carried out.

MAIN RESULTS

Ten of 52 eligible trials provided individual participant data, of which two were excluded after checking data integrity. The remaining eight trials compared low-dose vaginal misoprostol versus dinoprostone, including 4180 women undergoing IOL, which represents 32.8% of all participants in the published RCTs. Of these, 2077 were assigned to low-dose vaginal misoprostol and 2103 were assigned to vaginal dinoprostone. Compared with vaginal dinoprostone, low-dose vaginal misoprostol had a comparable rate of vaginal birth. Composite adverse perinatal outcomes did not differ between the groups. Compared with vaginal dinoprostone, composite adverse maternal outcomes were significantly lower with low-dose vaginal misoprostol (aOR 0.80, 95% CI 0.65-0.98, P = 0.03, I2 = 0%).

CONCLUSIONS

Low-dose vaginal misoprostol and vaginal dinoprostone for IOL are comparable in terms of effectiveness and perinatal safety. However, low-dose vaginal misoprostol is likely to lead to a lower rate of composite adverse maternal outcomes than vaginal dinoprostone.

Evaluation of the efficacy of labor induction with vaginal misoprostol in a low-risk pregnant women population

OBJECTIVE

The aim of this study was to evaluate the success rate and predictors of labor induction using vaginal misoprostol in a low-risk pregnant women population.

METHODS

A prospective cohort study was carried out with 196 pregnant women. Groups 2 and 4 of the Robson Classification admitted for induction of labor with vaginal misoprostol (25 μg tablets every 6 h, up to 4 tablets, for a maximum of 24 h). The success of labor induction was considered the achievement of vaginal delivery. Binary logistic regression was used to determine the best predictors of successful induction of labor with vaginal misoprostol.

RESULTS

Of all the pregnant women analyzed, 140 (71.4%) were successful and 56 (28.6%) were unsuccessful. Pregnant women who achieved successful induction had a higher number of pregnancies (1.69 vs. 1.36, p=0.023), a higher number of deliveries (0.57 vs. 0.19, p<0.001), a higher Bishop score (2.0 vs. 1.38, p=0.002), and lower misoprostol 25 μg tablets (2.18 vs. 2.57, p=0.031). No previous deliveries [x2(1)=3.14, odds ratio (OR): 0.24, 95% confidence interval (CI): 0.10-0.57, R2 Nagelkerke: 0.91, p=0.001] and the presence of one previous delivery [x2(1)=6.0, OR: 3.40, 95% CI: 1.13-10.16, R2 Nagelkerke: 0.043, p=0.029] were significant predictors of successful induction of labor with vaginal misoprostol.

CONCLUSION

A high rate of labor induction success using vaginal misoprostol in a low-risk population was observed, mainly in multiparous and with gestational age>41 weeks. No previous delivery decreased the success of labor induction, while one previous delivery increased the success of labor induction.

The effect of slow-release vaginal dinoprostone on maternal and fetal oxidative stress in term pregnancies complicated by oligohydramnios: Prospective cohort study

BACKGROUND

To evaluate changes in oxidant status using thiol/disulfide homeostasis in mothers and fetuses after induction of labor with slow-release vaginal dinoprostone inserts.

METHODS

A total of 70 pregnant women were divided into two groups. Thirty-five women in whom labor was induced with slow-release vaginal dinoprostone inserts (10 mg of prostaglandin E2, group A) were compared before and after the administration. The other 35 women, who were followed up spontaneously during labor (group B), were included as a control group. Both groups were diagnosed with isolated oligohydramnios without signs of placental insufficiency. The thiol/disulfide homeostasis parameters were calculated before medical induction and after removal of the insert at the beginning of the active phase of labor. Maternal and cord blood values were measured in both groups.

RESULTS

Although the balance shifted to the antioxidant side after the slow-release vaginal dinoprostone insert was applied, there was no significant difference in maternal oxidative load compared to the pre-application status (5.32 ± 014/5.16 ± 0.15, p = 0.491). Despite the shift toward the antioxidant side, maternal antioxidants were still significantly lower in the group that received slow-release vaginal dinoprostone at the beginning of the active phase of labor than in the control group (295.98 ± 13.03/346.47 ± 12.04, respectively, p = 0.009). There was no statistically significant difference in terms of oxidative balance or newborn Apgar score ( p > 0.05).

CONCLUSION

Induction of labor with slow-release vaginal dinoprostone inserts in pregnancies with isolated oligohydramnios does not cause further oxidative stress and is safe for both mothers and neonates in terms of oxidant load by thiol/disulfide homeostasis.

Safety of misoprostol vs dinoprostone for induction of labor: A systematic review and meta-analysis

OBJECTIVE

Pharmacological agents such as prostaglandins (dinoprostone and misoprostol) are commonly used to reduce the duration of labor and promote vaginal delivery. However, key safety considerations with its use include an increased risk of uterine rupture, tachysystole and hyperstimulation of pregnant women, which could potentially lead to a non-reassuring fetal heart rate and to fetal hypoxemia. The aim of this systematic review was to assess maternal and fetal outcomes between misoprostol group (PGE1) and dinoprostone group (PGE2) STUDY DESIGN: We search on MEDLINE (PubMed), CINHAL (EBSCOhost), EMBASE, Scopus (Ovid), CENTRAL (January 1, 1998, to December 31, 2022). Patients were eligible if they presented at greater than 36 weeks gestation with an indication for induction of labor and a single live cephalic fetus. We conducted a meta-analysis of data for both primary (cesarean section rate, instrumental deliveries rate, tachysystole, uterine rupture, post-partum haemorrage; chorionamiositis) and secondary outcomes (Apgar at 5 min <7, meconium-stained liquor, NICU admission, infant death) using odds-ratio (OR) as a measure of effect-size. Risk of bias assessment was performed with RoB-I. We performed statistical analyses using Cochrane RevMan version 5.4 software.

RESULTS

We found 39 RCTs comparing the outcomes of interest between misoprostol and dinoprostone. The pooled effect showed no statistically significant difference between the two groups in terms of cesarean section rate [OR: 0.94; 95% CI 0.84-1.05], instrumental deliveries rate [OR: 1.04; 95% CI: 0.90-1.19; p = 0.62], tachysystole [OR: 1.21; 95% CI: 0.91-1.60; p = 0.19], post-partum hemorrhage [OR: 0.85; 95% CI: 0.62-1.15p = 0.30], chorioamnionitis [OR: 0.94; 95% CI: 0.76-1.17p = 0.59], Apgar at 5 min < 7 [OR: 0.83; 95% CI: 0.61-1.12, p = 0.21], meconium-stained liquor [OR: 1.11; 95% CI: 0.97-1.27p = 0.59], NICU admission group [OR: 0.91; 95% CI: 0.77-1.09], infant death [OR: 0.57; 95% CI: 0.22-1.44]. After performing a sub-group analysis based on the type of prostaglandins administrations (oral, vaginal gel, vaginal pessary), results did not change substantially.

CONCLUSIONS

This systematic review and meta-analysis demonstrate that misoprostol and dinoprostone appear to have a similar safety profile.

The effect of evening primrose oil on cervical ripening and birth outcomes: A systematic review and meta-analysis

Background and purpose

The results of various studies on the effect of evening primrose oil (EPO) on cervical ripening are controversial. The purpose of this systematic review and meta-analysis was to assess the effect of EPO on cervical ripening and birth outcomes.

Materials and methods

The Cochrane Library, Embase, PubMed, Scopus, Web of Science and Persian databases were searched for studies published from the inception of the databases up to February 2021 (search updated in May 2022). Full-text articles published in English or other languages, randomized controlled trials, and quasi experimental studies with control group were included. Studies published in form of conference proceedings, and those whose full texts were not available, as well as studies with control groups receiving other treatments for cervical ripening, and those in which the intervention group received drugs besides EPO were all excluded. The Cochrane handbook was used to determine the risk of bias of the included studies. All data were analyzed using Review Manager 5.4 and reported in forest plots.

Results

Seven trials involving 920 women were included in the meta-analysis. In five studies, including 652 participants, cervical ripening was evaluated using Bishop score. The use of EPO was found to significantly improved Bishop score (MD = 3.23; 95% CI: 3.17, 3.29). The meta-analysis showed no significant differences between two comparison groups in terms of 1-min Apgar score and length of the second stage of labor. However, the two groups were significantly different in terms of their 5-min Apgar score and the time interval between administration of EPO and birth. Based on subgroup analysis by route of administration, both vaginal and oral use of EPO increased Bishop score significantly in the intervention group compared to the placebo group.

Conclusion

This study showed that using EPO in term and post-term pregnant women was clinically effective in improving their Bishop score.

The impact of vaginal pH on induction of labour outcomes: a meta-analysis of observational studies

The present meta-analysis evaluates the impact of an acidic vaginal pH on the progress of labour induction with dinoprostone and misoprostol. We searched Medline, Scopus, EMBASE, Cochrane Central Register of Controlled Trials CENTRAL, Clinicaltrials.gov and Google Scholar databases for relevant studies. Meta-analysis was performed with Rstudio using the meta function and trial sequential analysis was used to evaluate the adequacy of sample size. Nine studies were retrieved that involved 809 patients. An acidic vaginal pH did not influence the efficacy of misoprostol or dinoprostone in terms of accomplishing a successful vaginal delivery (OR 0.62, 95% CI 0.29, 1.30). The interval to delivery was unaffected by the acidity of vaginal pH (Mean Difference 4.18 h, 95% CI -2.09, 10.45). In conclusion, vaginal pH does not seem to affect the potency of vaginally administered prostaglandins; therefore, moistening of vaginal tables with acetic acid does not seem reasonable until further evidence becomes available.

Labor induction with prostaglandin E1 versus E2: a comparison of outcomes

OBJECTIVE

To compare the peripartum outcomes when labor is induced with prostaglandins E₁ versus E₂.

METHODOLOGY

The Consortium of Safe Labor database was utilized. Women with non-anomalous singletons >24 weeks gestation undergoing induction were analyzed. The primary endpoint was a composite adverse maternal outcome with a composite adverse neonatal outcome as our secondary outcome.

RESULTS

Of the 228,438 births within the database, 8229 (10.8%) met inclusion criteria with 4703 (55.7%) receiving PGE₁, and 3741 (44.3%), PGE₂. The rate of vaginal delivery was similar between both. Composite adverse maternal outcome, was more likely among the prostaglandin E₁: 7.2% vs. 1.5% (aOR 4.20; 95% CI 3.02-5.85); similar trend observed with composite adverse neonatal outcome rates: 4.6% vs. 1.4% (aOR 1.69; 95% CI 1.14-2.50).

CONCLUSION

Utilization of prostaglandin E₁, compared to E_2, was associated with an increased likelihood of adverse maternal and neonatal outcomes.

Comparison of effectiveness and safety of cervical ripening methods for induction of labour: A population-based study using coarsened exact matching

BACKGROUND

There is no consensus about the ideal cervical ripening method to use for induction of labour.

OBJECTIVE

To compare in current practice the effectiveness and safety of four cervical ripening methods.

METHODS

We performed a matched comparative study using data from the MEDIP prospective population-based cohort conducted during one month in 2015 in all maternity units of seven French perinatal networks (3042 consecutive women with a live fetus and induction of labour). We analysed 1671 women with singleton cephalic fetus, unscarred uterus, and bishop score <7. Dinoprostone vaginal pessary (reference) was compared to dinoprostone vaginal gel, misoprostol vaginal tablet, and balloon catheter. Effectiveness outcomes were the need for more than one induction agent, oxytocin use, failure to achieve vaginal delivery within 24 hours (VD < 24 hours), and caesarean delivery. Safety outcomes were meconium-stained amniotic fluid, uterine hyperstimulation, NICU admission, and post-partum haemorrhage. Coarsened exact matching was used to balance confounders among the groups. Outcomes were compared using multivariable logistic regression models.

RESULTS

Compared to the dinoprostone pessary (N = 1142, 68.3%), dinoprostone gel (N = 335, 20.1%) was associated with less failure to achieve VD < 24 hours (adjusted OR 0.66, 95% CI 0.47, 0.91). Misoprostol (N = 103, 6.2%) was associated with less need of more than one induction agent (aOR 0.56, 95% CI 0.34, 0.92) and less oxytocin use (aOR 0.60, 95% CI 0.37, 0.99). The balloon catheter (N = 91, 5.4%) was associated with more failure to achieve VD < 24 hours (aOR 2.62, 95% CI 1.37, 5.01), more caesarean delivery (aOR 1.84, 95% CI 1.09, 3.08), and less meconium-stained amniotic fluid (aOR 0.12, 95% CI 0.02, 0.70). Uterine hyperstimulation rates seemed lower with the balloon catheter (1.2% vs 4.2% for the pessary).

CONCLUSIONS

In current practice, no cervical ripening method appears clearly superior to the others considering all effectiveness and safety outcomes.

Misoprostol vaginal insert (Mysodelle) versus Dinoprostone intravaginal gel (Prostin) for induction of labour

OBJECTIVE

The aim of this study is the compare the effectiveness and safety of Misoprostol Vaginal Insert (Mysodelle) versus Dinoprostone intravaginal gel (Prostin) for induction of labour.

STUDY DESIGN

We performed a prospective cohort study of the use of misoprostol vaginal inserts (Mysodelle) in the induction of pregnancy and compared it to a historical cohort of women induced with the Dinoprostone intravaginal gel (Prostin) at the Liverpool Women's Hospital, a large UK teaching hospital.

RESULTS

A total of 4102 women were induced between December 2016 and September 2018 of whom 2540 were induced with dinoprostone gel until September 2017. Since October 2017 1562 were induced using misoprostol vaginal inserts (MVI). The MVI demonstrated a significantly quicker median time to delivery compared with dinoprostone gel (18.2 h versus 21.8 h; p < 0.0001). There was a 32% reduced risk of Caesarean section with MVI (7.5% vs 10.9%; RR 0.62 95%CI 0.56-0.84) There was no significant difference in any of the key maternal or neonatal adverse outcomes.

CONCLUSIONS

The results of this study suggest that misoprostol vaginal inserts, compared with dinoprostone intravaginal gel, achieve quicker delivery times, and a reduction in caesarean sections with no increased rate of adverse maternal or neonatal outcomes.

[Overview of induction of labor practices in France]

OBJECTIVE

To describe induction of labor practices in France and to identify factors associated with the use of different methods.

METHODS

The data came from the French prospective population-based cohort MEDIP (MEthodes de Déclenchement et Issues Périnatales), including consecutively during one month in 2015 all women with induction of labor and a live fetus in 7 perinatal networks. The characteristics of women, maternity units, gestational age, Bishop's score, decision mode, indication and methods of labor induction were described. Factors associated with the use of different methods were sought in univariate analyzes.

RESULTS

The rate of induction of labor during the study was 21% and 3042 women were included (95.9% participation rate). The two main indications were prolonged pregnancy (28.7%) and premature rupture of the membranes (25.4%). More than one-third of women received intravenous oxytocin in first method, 57.3% prostaglandins, 4.5% balloon catheter and 1.4% another method. Among the prostaglandins, the vaginal device of dinoprostone was the most used (71.6%) then the gel (20.7%) and the vaginal misoprostol (6.7%). Women with a balloon were more often of higher body mass index and multiparous with scarred uterus. The balloon and misoprostol were mainly used in university public hospitals.

CONCLUSIONS

The evolution of induction of labor methods, due to new data from the literature and the development of new drugs or devices, invites to regularly repeat population-based studies on induction of labor.

Low-dose vaginal misoprostol vs vaginal dinoprostone insert for induction of labor beyond 41st week: A randomized trial

INTRODUCTION

The aim of this study was to compare the efficacy and safety of a low-dose protocol of vaginal misoprostol and vaginal dinoprostone insert for induction of labor in women with post-term pregnancies.

MATERIAL AND METHODS

We designed a prospective, randomized, open-labeled trial with evaluators blinded to the end-point, including women of at least 41 weeks of gestational age with uncomplicated singleton pregnancies and a Bishop score <6. They were randomized into dinoprostone or misoprostol groups in a 1:1 ratio. Baseline maternal data and perinatal outcomes were recorded for statistical analysis. Successful vaginal delivery within 24 hours was the primary outcome variable. A P value <0.05 was considered statistically significant. This study was registered in ClinicalTrials.gov (number NTC03744364).

RESULTS

We included 198 women for analysis (99 women in each group). Vaginal birth rate within 24 hours did not differ between groups (49.5% vs 42.4%; P = 0.412). When the Bishop score was <4, dinoprostone insert showed a higher probability of vaginal delivery within 12 hours (17.8% vs 4%; P = 0.012). In the dinoprostone group, removal of the insert was more likely to be due to an adverse event (5.1% vs 14.1%; P = 0.051) and an abnormal fetal heart rate pattern during active labor (44.4% vs 58.6%; P = 0.047). Both groups were similar in neonatal outcomes including Apgar score, umbilical cord pH and neonatal intensive care unit admission.

CONCLUSIONS

Low-dose vaginal misoprostol and vaginal dinoprostone insert seem to be equally effective and safe for induction of labor in pregnant women with a gestational age beyond 41 weeks.

A comparison of induction of labor success rates over three time periods in 20 years at a single academic tertiary care center: are we improving vaginal delivery rates?

OBJECTIVE

To compare the rates of successful induction of labor during three one-year periods over 20 years at a single institution.

METHODS

All women at 37 weeks or beyond with a living, singleton, cephalic fetus admitted for induction of labor in 1992, 2002, and 2012 were included. The use of induction agents and rates of successful vaginal delivery were compared.

RESULTS

A total of 627 women were evaluated, 219 in 1992, 220 in 2002, and 188 in 2012. Various induction agents were employed over the 20 year period. However, the rates of successful vaginal deliveries did not significantly vary over the three time periods, 79.5% in 1992, 72.3% in 2002, 76.1% in 2012, p = .21. In subgroup analysis, no significant differences were found among women with one or more prior vaginal delivery, no prior vaginal delivery, or after excluding those with a prior cesarean section. In multiple variable logistic regression analysis, no induction agent besides amniotomy improved successful vaginal delivery rates.

CONCLUSIONS

Despite the multiple induction agents available at our tertiary care institution over the past 20 years, we were unable to demonstrate any significant improvement in successful vaginal delivery rates after induction of labor.