A double-blind comparison of the safety and efficacy of intravaginal misoprostol and prostaglandin E2 to induce labor

Vaginal dinoprostone insert compared with two different oral misoprostol regimens for labor induction in nulliparous and multiparous women

INTRODUCTION

Labor induction exhibits considerable variations in protocols and medication regimens. Limited studies compare vaginal dinoprostone inserts with different oral misoprostol dosages, considering parity influence. This study explores the distinctions among 10 mg vaginal dinoprostone inserts and oral misoprostol 25 μg every 2 and every 4 h for labor induction, stratified by parity.

MATERIAL AND METHODS

This retrospective cohort study involved 607 participants across two hospitals. The primary outcome, time from induction to delivery, and secondary outcomes, including mode of delivery and maternal and fetal safety, were assessed.

RESULTS

Patient characteristics revealed differences in indication for labor induction, with the dinoprostone cohort having fewer post-term and premature rupture of membranes cases but more intrauterine growth restriction/small-for-gestational age. Both oral misoprostol regimens showed a shorter time to delivery interval compared to the dinoprostone cohort (median: 1380 min [IQR 1381.0] and 1127.0 min [IQR 1214.0] vs 1631.5 [IQR 1736.2], p < 0.001 and p = 0.014). Only the difference between oral misoprostol q2h and vaginal dinoprostone remained significant for nulliparous but not multiparous women, losing significance over all the population after adjusting for confounding factors. The proportion of women giving birth within 24 h did not significantly differ between misoprostol q2h and dinoprostone after adjusting for confounders. When comparing misoprostol q4h with dinoprostone after confounder adjustment, an increased time to delivery interval for misoprostol q4h was found (p = 0.001). Both oral misoprostol regimens exhibited fewer meconium-stained liquor (miso q4h: OR 0.44, miso q2h: OR 0.34) and cesarean sections (miso q4h: OR 0.48, miso q2h: OR 0.53) compared to dinoprostone, even after adjustment for confounders.

CONCLUSIONS

Our study suggests that oral misoprostol 25 μg q4h is less effective than 10 mg vaginal dinoprostone for labor induction if parity and indication for induction are adjusted for, particularly in multiparous women. In terms of side effects, oral misoprostol regimens seem superior to vaginal dinoprostone. Our data support the individualized use of different agents for labor induction according to parity, indication for induction, bishop score, and women's preference.

Safety and Efficacy of Cervical Ripening and Induction of Labor Using Prostaglandin E1 in Primiparas, Multiparas and Grand Multiparas

Objective

To compare the efficacy and safety of cervical ripening and induction of labor with prostaglandin E1 among primiparas, multiparas and grand multiparas.

Study design

This was a retrospective cohort study.

Results

Between January and December 2017, 1713 women underwent cervical ripening and induction of labor with prostaglandin E1: 523 were primiparas, 656 were multiparas, and 534 were grand multiparas. Four hundred and seventy-nine (91.6%) primiparas delivered vaginally as did 640 (97.6%) multiparas and 521 (97.6%) grand multiparas. Forty-four (8.4%) primiparas underwent cesarean delivery compared to 16 (2.4%) multiparas and 13(2.4%) grand multiparas. Induction to delivery interval was significantly longer in primiparas (29.7 ± 22.8 h). There were no cases of uterine rupture, and the rates of postpartum hemorrhage and endometritis were similar among the three groups. Neonatal outcomes including Apgar score < 7 and umbilical artery pH < 7.1 were not significantly different between the groups.

Conclusion

Using prostaglandin E1 for cervical ripening and labor induction is efficient and safe in primiparas, multiparas and grand multiparas.

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.

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.

Misoprostol vaginal insert versus misoprostol vaginal tablets for the induction of labour: a cohort study

Background

Misoprostol vaginal insert for induction of labor has been recently reported to be superior to dinoprostone vaginal insert in a phase III trial, but has never been compared to vaginal misoprostol in another galenic form. The aim of this study was to compare misoprostol vaginal insert (MVI) with misoprostol vaginal tablets (MVT) for induction of labor in term pregnancies.

Methods

In this retrospective cohort study we compared 200 consecutive women induced with 200-μg misoprostol 24-h vaginal insert (Misodel®) with a historical control of 200 women induced with Misoprostol 25-μg vaginal tablets (Cytotec®) every 4-6 h. Main outcomes variables included induction-to-delivery interval, vaginal delivery within 24-h, incidence of tachysystole, mode of delivery, and neonatal outcome. A subanalysis in the MVI group was performed in order to identify predictive factors for tachysistole and vaginal delivery within 24 h.

Results

The time from induction to vaginal delivery was 1048 ± 814 min in the MVI group and 1510 ± 1043 min in the MVT group (p < 0.001). Vaginal delivery within 24-h occurred in 127 (63.5%) patients of the MVI group and in 110 (55%) patients of the MVT group (p < 0.001). Tachysystole was more common in the MVI group (36% vs. 18%; p < 0.001). However, no significant predictors of uterine tachysystole in MVI group have been identified in crude and fully adjusted logistic regression models. Bishop score was the only predictor for vaginal delivery within 24 h (p < 0.001) in MVI group. Caesarean delivery rate (27% vs. 20%) and vaginal-operative deliveries (15.5% vs. 15.5%) did not differ significantly between the two groups. Neonatal outcomes were similar in both groups.

Conclusions

MVI achieves a more vaginal delivery rate within 24 h and Tachysystole events compared to MVT. However, no differences in caesarean section, operative vaginal delivery, and neonatal outcomes are reported. No predictors of tachysistole after MVI administration have been identified. Bishop score and parity are the only predictors of vaginal delivery within 24 h after MVI administration.

Which method is best for the induction of labour? A systematic review, network meta-analysis and cost-effectiveness analysis

BACKGROUND

More than 150,000 pregnant women in England and Wales have their labour induced each year. Multiple pharmacological, mechanical and complementary methods are available to induce labour.

OBJECTIVE

To assess the relative effectiveness, safety and cost-effectiveness of labour induction methods and, data permitting, effects in different clinical subgroups.

METHODS

We carried out a systematic review using Cochrane methods. The Cochrane Pregnancy and Childbirth Group's Trials Register was searched (March 2014). This contains over 22,000 reports of controlled trials (published from 1923 onwards) retrieved from weekly searches of OVID MEDLINE (1966 to current); Cochrane Central Register of Controlled Trials (The Cochrane Library); EMBASE (1982 to current); Cumulative Index to Nursing and Allied Health Literature (1984 to current); ClinicalTrials.gov; the World Health Organization International Clinical Trials Registry Portal; and hand-searching of relevant conference proceedings and journals. We included randomised controlled trials examining interventions to induce labour compared with placebo, no treatment or other interventions in women eligible for third-trimester induction. We included outcomes relating to efficacy, safety and acceptability to women. In addition, for the economic analysis we searched the Database of Abstracts of Reviews of Effects, and Economic Evaluations Databases, NHS Economic Evaluation Database and the Health Technology Assessment database. We carried out a network meta-analysis (NMA) using all of the available evidence, both direct and indirect, to produce estimates of the relative effects of each treatment compared with others in a network. We developed a de novo decision tree model to estimate the cost-effectiveness of various methods. The costs included were the intervention and other hospital costs incurred (price year 2012-13). We reviewed the literature to identify preference-based utilities for the health-related outcomes in the model. We calculated incremental cost-effectiveness ratios, expected costs, utilities and net benefit. We represent uncertainty in the optimal intervention using cost-effectiveness acceptability curves.

RESULTS

We identified 1190 studies; 611 were eligible for inclusion. The interventions most likely to achieve vaginal delivery (VD) within 24 hours were intravenous oxytocin with amniotomy [posterior rank 2; 95% credible intervals (CrIs) 1 to 9] and higher-dose (≥ 50 µg) vaginal misoprostol (rank 3; 95% CrI 1 to 6). Compared with placebo, several treatments reduced the odds of caesarean section, but we observed considerable uncertainty in treatment rankings. For uterine hyperstimulation, double-balloon catheter had the highest probability of being among the best three treatments, whereas vaginal misoprostol (≥ 50 µg) was most likely to increase the odds of excessive uterine activity. For other safety outcomes there were insufficient data or there was too much uncertainty to identify which treatments performed 'best'. Few studies collected information on women's views. Owing to incomplete reporting of the VD within 24 hours outcome, the cost-effectiveness analysis could compare only 20 interventions. The analysis suggested that most interventions have similar utility and differ mainly in cost. With a caveat of considerable uncertainty, titrated (low-dose) misoprostol solution and buccal/sublingual misoprostol had the highest likelihood of being cost-effective.

LIMITATIONS

There was considerable uncertainty in findings and there were insufficient data for some planned subgroup analyses.

CONCLUSIONS

Overall, misoprostol and oxytocin with amniotomy (for women with favourable cervix) is more successful than other agents in achieving VD within 24 hours. The ranking according to safety of different methods was less clear. The cost-effectiveness analysis suggested that titrated (low-dose) oral misoprostol solution resulted in the highest utility, whereas buccal/sublingual misoprostol had the lowest cost. There was a high degree of uncertainty as to the most cost-effective intervention.

FUTURE WORK

Future trials should be powered to detect a method that is more cost-effective than misoprostol solution and report outcomes included in this NMA.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42013005116.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Induction of labor in twin pregnancies with oral misoprostol versus vaginal dinoprostone--is it effective and safe?

OBJECTIVE

To compare the effectiveness and safety of oral misoprostol versus vaginal dinoprostone for the induction of labor in twin pregnancies.

METHODS

All twin pregnancies ≥ 34 weeks 0 days that were induced with either misoprostol or dinoprostone in St. Hedwig Hospital between 2002 and 2013 were included in this retrospective study. Length of induction, mode of delivery, maternal and neonatal outcomes were compared between the two groups.

RESULTS

After identifying 186 twin mothers matching the inclusion criteria, 154 women were induced with misoprostol (group A) and 32 with dinoprostone (group B). There were no differences in demographic data between the groups. Rates of successful vaginal delivery (53.9% versus 56.3%) and length of induction to delivery (30.2 h versus 26.9 h) were also similar. There were slightly higher rates of postpartum hemorrhage in group B (16.6% versus 10.8%), but without reaching statistical significance. Neonatal outcomes regarding umbilical artery pH <7.20 and one minute Apgar also were without significant differences.

CONCLUSIONS

Study data indicate that oral misoprostol and vaginal dinoprostone are similarly effective and safe for the induction of labor in twin gestations. Further trials with larger series are needed to confirm these results.

Labor Induction with 50 μg Vaginal Misoprostol: Can We Reduce Induction-Delivery Intervals Safely?

OBJECTIVE

To compare the efficacy and safety profile of two methods of labor induction i.e., intracervical dinoprostone gel (0.5 mg 8 h) and misoprostol (50 μg 4 h) for induction of labor in women with a poor Bishop's score.

DESIGN

Observational study.

STUDY PERIOD

January 1st, 2009 to December 31st, 2010.

POPULATION

A total of 329 women with unfavorable cervices induced at or near term.

METHODS

Two cervical ripening agent study arms were used: dinoprostone gel (193 women) and misoprostol (137 women).

MAIN OUTCOME MEASURES

Induction to delivery interval, cesarean section, incidence of meconium stained liquor, FHR pattern, incidence of uterine hyperstimulation, and neonatal outcomes.

RESULTS

The induction to delivery interval was significantly shorter in the misoprostol group as compared to the dinoprostone group (p < 0.001). There was no difference in cesarean section rates between the two groups (dinoprostone gel 43 %; misoprostol 33 %; p = 0.144). The incidence of non-reassuring fetal heart rate pattern, meconium stained liquor, and uterine hyperstimulation were equivalent in both the groups (p = 0.529; 0.733; and 0.321, respectively). The neonatal outcomes in both the groups were comparable in terms of Apgar scores at birth (p = 0.160) and NICU admissions (p = 0.951).

CONCLUSIONS

Labor induction in women with unfavorable cervices results in high caesarean section rates. However, the use of misoprostol significantly reduces the induction to delivery interval, without adversely affecting the caesarean section rates and neonatal outcomes. Hence it may become a cost-effective alternative to dinoprostone gel in resource-poor settings like India.

Off-label use of misoprostol for labor induction: a nation-wide survey in Switzerland

OBJECTIVE

Off-label use of drugs is frequent in obstetrical practice. No data however are available about nation-wide off-label use in obstetrics regarding frequency and patient information. The objective of our study was to assess the clinical practice of off-label use of misoprostol for labor induction.

STUDY DESIGN

We performed a prospective nation-wide survey study by means of a validated questionnaire in three languages in Switzerland. All registered obstetricians/gynaecologists in Switzerland were included. Of 1100 subjects, 725 (66%) answered the questionnaire; 69 subjects were excluded because they were not actively practicing OB/GYN, resulting in a total of 656 questionnaires included in the analysis.

RESULTS

A total of 512 out of 656 obstetricians/gynaecologists (78%) use misoprostol for labor induction. The most frequent administration route of misoprostol is intravaginal (86%), in a single dose of 50μg (94%), at a dose interval range from 4 to 6h (85%). Among the users of misoprostol, 314 (61%) answered that they do not inform their patients about the off-label use of the medication. Among the non-users of misoprostol, the main reason for non-use is absent license for obstetric indications (48%) and non-availability (14%). If misoprostol were to be licensed for this indication, and commercially available, 69% of current non-users would use it. Non-users of misoprotol use prostaglandin E2 vaginal gel, ovules or slow-release vaginal insert, and oxytocin for labor induction.

CONCLUSION

Misoprostol is the single most commonly used drug for labor induction in Switzerland, although it is not licensed and although there are effective, licensed alternative drugs available. A minority of practitioners inform the patients about the off-label use.

Vaginal misoprostol for cervical ripening and induction of labour

BACKGROUND

Misoprostol (Cytotec, Searle) is a prostaglandin E1 analogue widely used for off-label indications such as induction of abortion and of labour. This is one of a series of reviews of methods of cervical ripening and labour induction using standardised methodology.

OBJECTIVES

To determine the effects of vaginal misoprostol for third trimester cervical ripening or induction of labour.

SEARCH STRATEGY

The Cochrane Pregnancy and Childbirth Group's Trials Register (November 2008) and bibliographies of relevant papers. We updated this search on 30 April 2010 and added the results to the awaiting classification section.

SELECTION CRITERIA

Clinical trials comparing vaginal misoprostol used for third trimester cervical ripening or labour induction with placebo/no treatment or other methods listed above it on a predefined list of labour induction methods.

DATA COLLECTION AND ANALYSIS

We developed a strategy to deal with the large volume and complexity of trial data relating to labour induction. This involved a two-stage method of data extraction.We used fixed-effect Mantel-Haenszel meta-analysis for combining dichotomous data.If we identified substantial heterogeneity (I² greater than 50%), we used a random-effects method.

MAIN RESULTS

We included 121 trials. The risk of bias must be kept in mind as only 13 trials were double blind.Compared to placebo, misoprostol was associated with reduced failure to achieve vaginal delivery within 24 hours (average relative risk (RR) 0.51, 95% confidence interval (CI) 0.37 to 0.71). Uterine hyperstimulation, without fetal heart rate (FHR) changes, was increased (RR 3.52 95% CI 1.78 to 6.99).Compared with vaginal prostaglandin E2, intracervical prostaglandin E2 and oxytocin, vaginal misoprostol was associated with less epidural analgesia use, fewer failures to achieve vaginal delivery within 24 hours and more uterine hyperstimulation. Compared with vaginal or intracervical prostaglandin E2, oxytocin augmentation was less common with misoprostol and meconium-stained liquor more common.Lower doses of misoprostol compared to higher doses were associated with more need for oxytocin augmentation and less uterine hyperstimulation, with and without FHR changes.We found no information on women's views.

AUTHORS' CONCLUSIONS

Vaginal misoprostol in doses above 25 mcg four-hourly was more effective than conventional methods of labour induction, but with more uterine hyperstimulation. Lower doses were similar to conventional methods in effectiveness and risks. The authors request information on cases of uterine rupture known to readers. The vaginal route should not be researched further as another Cochrane review has shown that the oral route of administration is preferable to the vaginal route. Professional and governmental bodies should agree guidelines for the use of misoprostol, based on the best available evidence and local circumstances.

Labor induction in preeclampsia: is misoprostol more effective than dinoprostone?

OBJECTIVE

To compare the efficacy of vaginal misoprostol versus dinoprostone for induction of labor (IOL) in patients with preeclampsia according to the WHO criteria.

STUDY DESIGN

Ninety-eight patients were retrospectively analyzed. A total of 47 patients received 3 mg dinoprostone suppositories every 6 h (max. 6 mg/24 h) whereas 51 patients in the misoprostol group received either 50 mug misoprostol vaginally every 12 h, or 25 mug every 6 h (max. 100 mug/24 h). Primary outcomes were vaginal delivery within 24 and 48 h, respectively.

RESULTS

The probability of delivering within 48 h was more than three-fold higher in the misoprostol than in the dinoprostone group: odds ratio (OR)=3.48; 95% confidence interval (CI) 1.24, 10.30, whereas no significant difference was observed within 24 h (P=0.34). No correlation was seen between a ripe cervix prior to IOL and delivery within 24/48 h (P=0.33 and P=1.0, respectively). More cesarean sections were performed in the dinoprostone group due to failed IOL (P=0.0009). No significant differences in adverse maternal outcome were observed between both study groups, whereas more neonates (12 vs. 6) of the dinoprostone group were admitted to the NICU (P=0.068).

CONCLUSION

This study suggests that misoprostol may have some advantages compared to dinoprostone, including improved efficacy and lower cost of the drug, even in cases of preeclampsia.

Misoprostol compared with prostaglandin E2 for labour induction in women at term with intact membranes and unfavourable cervix: a systematic review*

BACKGROUND

Misoprostol is a commonly used prostaglandin to induce labour. A potential risk of induction, however, is caesarean delivery, especially in women with an unfavourable cervix.

OBJECTIVES

To evaluate the use of misoprostol, compared with prostaglandin E2 (PgE2), for labour induction in women at term with an unfavourable cervix and intact membranes.

SEARCH STRATEGY

PubMed, Medline, EMBASE and the Cochrane Library were searched for articles published in any language from January 1987 to December 2005, using the keywords 'misoprostol', 'labour/labor' and 'induction'.

SELECTION CRITERIA

We identified randomised trials of women at term (> or =37 weeks of gestation) with intact membranes and unfavourable cervix, undergoing labour induction with misoprostol, orally, vaginally, sublingually or buccally, compared with PgE2 vaginally or intracervically.

DATA COLLECTION AND ANALYSIS

Caesarean delivery was the primary outcome, with tachysystole and hyperstimulation as secondary outcomes. The primary analysis compared any misoprostol with any PgE2 for all women, with a subgroup analysis for nulliparous women. Secondary analyses compared different routes and doses of misoprostol (oral or vaginal and 25 microgram or >25 microgram) and PgE2 (intracervical or vaginal). Relative risks (RR) and 95% confidence intervals (CI) were calculated using random effects models. Main results Fourteen of 611 articles identified met the criteria for systematic review, with three providing information for nulliparous women. There was no difference in the risk of caesarean delivery between misoprostol and PgE2 groups (RR = 0.99, 95% CI = 0.83-1.17). Any misoprostol was associated with higher risks of tachysystole and hyperstimulation compared with any PgE2 (RR = 1.86, 95% CI = 1.01-3.43 and RR = 3.71, 95% CI = 2.00-6.88, respectively). There was a higher rate of vaginal delivery within 24 hours among all vaginal deliveries with any misoprostol compared with any PgE2 (RR = 1.14, 95% CI = 1.00-1.31), and among all deliveries, a lower rate of oxytocin use (RR = 0.71, 95% CI = 0.60-0.85) but a trend towards increased meconium staining was observed (RR = 1.22, 95% CI = 0.96-1.55). The use of misoprostol at starting dosages >25 microgram had similar findings to the primary analysis. Studies of lower misoprostol dosing (starting dose of 25 microgram) did not show any differences in the outcomes of interest, but the sample size of this secondary analysis was small (304 women, 155 receiving misoprostol).

AUTHOR'S CONCLUSIONS

Although misoprostol in women at term with an unfavourable cervix and intact membranes was more effective than PgE2 in achieving vaginal delivery within 24 hours, misoprostol does not reduce the rate of caesarean delivery either in all women or in the subgroup of nulliparous women, and it increases the rates of tachysystole and hyperstimulation. Further studies of misoprostol using a starting dose of 25 microgram may be warranted.

A randomized comparison between intravaginal misoprostol and prostaglandin E2 for labor induction

OBJECTIVE

The aim of this randomized study was to compare the effectiveness, safety, and side effects of 6 h vaginal misoprostol versus vaginal prostaglandin E(2) (PGE(2)) for labor induction.

STUDY DESIGN

Fifty microgram of misoprostol was given intravaginally in the misoprostol group (204 women), and 3 mg PGE(2) was given intravaginally in the PGE(2) group (211 women). In both groups, the dose was repeated every 6 h for a maximum of three doses, until active labor was achieved. Artificial rupture of membranes and oxytocin infusion was used during labor in both groups where it was indicated.

RESULTS

The mean interval from the institution of labor induction to delivery was 11.3 +/- 8.6 h for the misoprostol group, and 15.7 +/- 9.3 h for PGE(2 )group (P < 0.05). In the misoprostol group, oxytocin was used less frequently, but there was a higher prevalence of tachysystole. No statistically significant differences were observed between the two groups as regard abnormal patterns of fetal heart rate, the mode of delivery, and the need for neonatal intervention.

CONCLUSION

In conclusion, the intravaginal administration of 50 mug misoprostol at 6 h interval (maximum three doses) is comparable in safety, but more effective for induction of labor than 3 mg intravaginal PGE(2).

Vaginal Misoprostol Administration for Cervical Ripening and Labor Induction

Intravaginal misoprostol has been shown to be an effective agent for cervical ripening and induction of labor. Vaginal application of misoprostol has been reported in over 9000 women worldwide and seems to have safety profile similar to that of endocervically and intravaginally administered dinoprostone. Concern arises with the use of higher doses of intravaginal misoprostol (50 mcg or more) and the association with uterine contractile abnormalities and for this reason, use of low-dose misoprostol regimen has been recommended by the American College of Obstetricians and Gynecologists. The recommendation is use of a 25-mcg dose of misoprostol inserted into the posterior vaginal fornix and repeated every 3 to 6 hours as needed. Misoprostol administration to women with prior cesarean births seems to increase the likelihood of uterine scar disruption and should not be used in these women. There are reports of uterine rupture in women with unscarred uteri treated with vaginally applied misoprostol. Therefore, all patients need to be monitored adequately after misoprostol administration. Although there is a growing body of data regarding the ambulatory use of intravaginal misoprostol for cervical ripening, its use for this purpose cannot be recommended outside of investigational protocols at this time because of concerns for maternal and neonatal safety.

Intravaginal glyceryl trinitrate and dinoprostone for cervical ripening and induction of labor

OBJECTIVE

This study was undertaken to evaluate the efficacy and safety of intravaginal administration of glyceryl trinitrate plus dinoprostone versus dinoprostone, for cervical ripening and induction of labor.

STUDY DESIGN

A prospective, double-blind, placebo-controlled, randomized clinical trial was conducted among 196 singleton low-risk nullipara women with term pregnancies and unfavorable cervices who were randomly assigned to receive intravaginal glyceryl trinitrate plus dinoprostone or placebo plus dinoprostone. The main outcome variables were time from application to active phase of labor and to delivery. Secondary outcomes were change in Bishop score, fetal and maternal morbidity, and incidence of cesarean deliveries.

RESULTS

The interval from application of the initial dose to the beginning of active phase of labor was 868 +/- 582 and 1136 +/- 692 minutes (P = .004) and from initial dose to delivery was 1339 +/- 826 and 1620 +/- 975 minutes (P = .03) for the glyceryl trinitrate and placebo groups, respectively. There were no significant differences in Bishop score change, cesarean section rate, and in the incidence of hypersystole and hyperstimulation. The incidence of tachysystole was significantly lower in the glyceryl trinitrate group (4% vs 15%, P < or = .02). No maternal and neonatal adverse effects were noted.

CONCLUSION

The association of glyceryl trinitrate with dinoprostone is more effective than dinoprostone alone for labor induction in low-risk patients at term with unfavorable cervices.

[Efficacy and safety of misoprostol in obstetrics]

OBJECTIVE

To review the efficacy and safety of misoprostol for indications not included in the prescription information given for the product, including abortion, labor induction, treatment and prevention of postpartum bleeding, and hysteroscopy preparation.

METHOD

Pubmed was searched for controlled, randomized, blinded clinical trials of misoprostol in obstetrics from 1999 through 2004.

RESULTS

Nineteen clinical trials were found. The efficacy for abortion in association with mifepristone at a dosage of 400 microg/6 h is superior versus both placebo and gemeprost, but misoprostol is more painful and less effective than dilation and subsequent evacuation. Regarding the administration route, trials show similar efficacy for the vaginal and oral approaches. In the prevention and treatment of postpartum hemorrhage, misoprostol was not any better than oxytocin. When used as a labor inducing agent, results are best with doses of 50 microg/3-8 h, but no controlled clinical trials were found. Although its use for hysteroscopy facilitates the procedure versus placebo, it entails a higher frequency of adverse events. No controlled clinical trials were found for other options.

CONCLUSIONS

The efficacy of misoprostol for indications reviewed in this paper is controversial, and studies found are heterogeneous. Designing and conducting further clinical trials to investigate appropriate dosage and administration routes, as well as the drug s adverse effect profile under such circumstances is essential, and would potentially allow an application for approval to be filed with health authorities regarding its use in obstetric practice.

Influence of misoprostol or prostaglandin E(2) for induction of labor on the incidence of pathological CTG tracing: a randomized trial

OBJECTIVE

To compare the efficacy and safety of misoprostol (prostaglandin E(1) (PGE(1))) with dinoprostone (prostaglandin E(2) (PGE(2))) for third trimester cervical ripening and labor induction.

STUDY DESIGN

Patients requiring induction of labor were randomly assigned to receive either 50 microg of intravaginal misoprostol every 4 h or 0.5 mg of intracervical dinoprostone gel every 6 h. Eligibility criteria included gestation = 36 weeks. Primary outcome was the time interval from induction to delivery; secondary outcomes were mode of delivery, perinatal outcome, and interpretation of cardiotocogram (CTG) records.

RESULTS

Two hundred women were randomly enrolled to receive either misoprostol (n = 100) or dinoprostone (n = 100). Time induction-to-delivery at 12, 24 and 48 h and the need for oxytocin were reduced with misoprostol (P < 0.05). Pathological CTG tracing according to FIGO and Melchior scores were more frequent in the misoprostol-treated group (P < 0.001).

CONCLUSION

Misoprostol shortened the induction-to-delivery interval, but is associated with a higher incidence of abnormal CTG than prostaglandin E(2).

Cervical ripening with oral misoprostol at term

OBJECTIVES

To determine the efficacy of 200 microg single dose oral misoprostol as a cervical priming agent at term.

METHODS

In this double-blind randomized trial, 156 pregnant women requiring induction of labor with gestational age of 37-42 weeks and Bishop score < or =5, were randomized to receive either 200 microg of misoprostol or a placebo, orally. Labor was induced with intravenous oxytocin infusion 12 h after oral medication if the patient did not go into labor. The primary outcome was the change in the Bishop score 12 h after oral medication. The secondary outcomes were the timings starting from the drug administration to the onset of uterine activity, interval between oral medication and delivery, oxytocin need for induction, mode of delivery, frequency of side effects, and neonatal and maternal outcome. The chi-square or Fisher exact test, Student's t-test, and Mann-Whitney U-test were used for analysis of the data.

RESULTS

There were no significant differences in maternal characteristics or indications of induction. The Bishop score 12 h after oral medication significantly improved in the misoprostol group compared with the control group [55 (70%)>8 vs. 4 (5%)>8; P<0.001]. The induction rate was significantly reduced in the misoprostol group (P<0.001). The interval between oral medication and the onset of uterine activity was significantly shorter in the misoprostol group (P<0.001). The interval between oral medication and delivery was also significantly shorter in the misoprostol group (P<0.001). The cesarean delivery rate was significantly lower in the misoprostol group (P<0.001). There were no differences between the groups with respect to the incidence of tachysystole, hyperstimulation, adverse neonatal or maternal outcome.

CONCLUSIONS

Oral administration of 200 microg single dose of misoprostol is an effective agent not only for cervical priming but also for induction of labor at term. Furthermore, it reduces the rate of cesarean deliveries.

Induction of labor: the misoprostol controversy

Misoprostol (Cytotec) is safe and effective for induction of labor, although it is not approved by the Food and Drug Administration (FDA) for use in pregnancy. In August 2000, the manufacturer of misoprostol warned against its use in pregnancy because of its abortifacient properties and cited reports of maternal and fetal deaths when misoprostol was used to induce labor, fueling the misoprostol controversy. More than 45 randomized trials including more than 5400 women have found vaginal misoprostol to be more effective than oxytocin or vaginal prostaglandin E2 at effecting vaginal delivery within 24 hours. Cesarean delivery rates with vaginal misoprostol are lower than with oxytocin alone, but similar to prostaglandin E2. There have been no significant differences in the frequency of serious adverse maternal or neonatal outcomes with low-dose misoprostol compared with oxytocin or prostaglandin E2; however, the relative risk of rare adverse outcomes with misoprostol is unknown. The data suggest that absolute risks are low when misoprostol is used appropriately. We recommend 25 mcg vaginally every 4 to 6 hours for carefully selected patients in closely monitored settings. Whether misoprostol will prove to be the most cost-effective agent for inducing labor in women with an unfavorable cervix remains to be determined.

Vaginal misoprostol for cervical ripening and induction of labour

BACKGROUND

Misoprostol (Cytotec, Searle) is a prostaglandin E1 analogue marketed for use in the prevention and treatment of peptic ulcer disease. It is inexpensive, easily stored at room temperature and has few systemic side effects. It is rapidly absorbed orally and vaginally. Although not registered for such use, misoprostol has been widely used for obstetric and gynaecological indications, such as induction of abortion and of labour. This is one of a series of reviews of methods of cervical ripening and labour induction using standardised methodology.

OBJECTIVES

To determine the effects of vaginal misoprostol for third trimester cervical ripening or induction of labour.

SEARCH STRATEGY

The Cochrane Pregnancy and Childbirth Group trials register (October 2002), the Cochrane Controlled Trials Register (The Cochrane Library, Issue 3, 2002) and bibliographies of relevant papers.

SELECTION CRITERIA

The criteria for inclusion included the following: (1) clinical trials comparing vaginal misoprostol used for third trimester cervical ripening or labour induction with placebo/no treatment or other methods listed above it on a predefined list of labour induction methods; (2) random allocation to the treatment or control group; (3) adequate allocation concealment; (4) violations of allocated management not sufficient to materially affect conclusions; (5) clinically meaningful outcome measures reported; (6) data available for analysis according to the random allocation; (7) missing data insufficient to materially affect the conclusions.

DATA COLLECTION AND ANALYSIS

A strategy was developed to deal with the large volume and complexity of trial data relating to labour induction. This involved a two-stage method of data extraction. The initial data extraction was done centrally, and incorporated into a series of primary reviews arranged by methods of induction of labour, following a standardised methodology. The data will be extracted from the primary reviews into a series of secondary reviews, arranged by category of woman. To avoid duplication of data in the primary reviews, the labour induction methods have been listed in a specific order, from one to 25. Each primary review includes comparisons between one of the methods (from two to 25) with only those methods above it on the list.

MAIN RESULTS

Sixty-two trials have been included. Compared to placebo, misoprostol was associated with increased cervical ripening (relative risk of unfavourable or unchanged cervix after 12 to 24 hours with misoprostol 0.09, 95% confidence interval (CI) 0.03 to 0.24). It was also associated with reduced failure to achieve vaginal delivery within 24 hours (relative risk (RR) 0.36, 95% CI 0.19 to 0.68). Uterine hyperstimulation, without fetal heart rate changes, was increased (RR 11.7 95% CI 2.78 to 49). Compared with vaginal prostaglandin E2, intracervical prostaglandin E2 and oxytocin, vaginal misoprostol labour induction was associated with less epidural analgesia use, fewer failures to achieve vaginal delivery within 24 hours and more uterine hyperstimulation. Compared with vaginal or intracervical prostaglandin E2, oxytocin augmentation was less common, with misoprostol and meconium-stained liquor more common. Compared with intracervical prostaglandin E2, unchanged or unfavourable cervix after 12 to 24 hours was less common with misoprostol. Lower doses of misoprostol compared to higher doses were associated with more need for oxytocin augmentation, less uterine hyperstimulation, with and without fetal heart rate changes, and a non-significant trend to fewer admissions to neonatal intensive care unit. Use of a gel preparation of misoprostol versus tablet was associated with less hyperstimulation and more use of oxytocin and epidural analgesia. Information on women's views is conspicuously lacking.

REVIEWER'S CONCLUSIONS

Vaginal misoprostol appears to be more effective than conventional methods of cervical ripening and labour induction. The apparent increase in uterine hyperstimulation is of concern. Doses not exceeding 25 mcg four-hourly of concern. Doses not exceeding 25 mcg four-hourly appeared to have similar effectiveness and risk of uterine hyperstimulation to conventional labour inducing methods. The studies reviewed were not large enough to exclude the possibility of rare but serious adverse events, particularly uterine rupture, which has been reported anecdotally following misoprostol use in women with and without previous caesarean section. The authors request information on cases of uterine rupture known to readers. Further research is needed to establish the ideal route of administration and dosage, and safety. Professional and governmental bodies should agree guidelines for the use of misoprostol, based on the best available evidence and local circumstances.

A comparison of 100 microg oral misoprostol every 3 hours and 6 hours for labor induction: a randomized controlled trial

OBJECTIVE

To compare the efficacy and safety of 100 microg oral misoprostol for induction of labor between the regimen of 3 hour and 6 hour interval administration.

METHODS

Singleton pregnancies indicated for induction of labor between 34 and 42 weeks of gestation in the condition of unfavorable cervix (Bishop score < or = 4) and no contraindication for prostaglandins therapy were recruited into the study. All pregnant women were randomly assigned to receive 100 microg oral misoprostol every 3 hours or 6 hours until the cervix was favorable for amniotomy, spontaneous rupture of membranes or active labor occurred.

RESULTS

The mean time interval from induction to vaginal delivery was significantly shorter in the 3 hour interval group, compared with the 6 hour interval group (13.82 +/- 6.98h and 17.66 +/- 7.48h, P = 0.0019). There was no significant difference between the groups with regard to mode of delivery, analgesic requirement, maternal complication and neonatal outcome.

CONCLUSIONS

100 microg oral misoprostol every 3 hours is more effective for labor induction than every 6 hours but there was no difference in mode of delivery, analgesic requirement, maternal complications and neonatal outcome. A dose of 100 microg misoprostol orally every 3 hours seems to be the optimum regimen and the new option for labor induction. However, further study should be performed.

A benefit-risk assessment of misoprostol for cervical ripening and labour induction

Misoprostol, a prostaglandin E(1) analogue, is widely used in the US and other countries for cervical ripening and labour induction. Its use for these indications is not approved by the US Food and Drug Administration (FDA). The manufacturer of misoprostol issued a letter to American healthcare providers in August 2000, cautioning against the use of misoprostol in pregnant women and citing a lack of safety data for its use in obstetrical practice. The only FDA-approved indication in the product labelling is the treatment and prevention of intestinal ulcer disease resulting from nonsteroidal anti-inflammatory drug use. Multiple trials have proven that when applied vaginally, misoprostol is an effective agent for cervical ripening and labour induction in term pregnancy. The use of oxytocin augmentation is reduced when intravaginal misoprostol is used compared with other agents. Misoprostol use in obstetrics carries the added benefits of temperature stability at room temperature, which is unlike other prostaglandin preparations which require refrigeration or freezing, and reduced cost. However, debate continues regarding the optimal dose, dosage regimen, and route of administration. Uterine contraction abnormalities are often found in association with higher misoprostol doses (50 microg or more) given vaginally or orally. Some trials also indicate increased frequencies of meconium passage, neonatal acidaemia and caesarean delivery for fetal distress in women receiving higher doses of vaginally applied misoprostol. However, most trials fail to demonstrate a significant change in the caesarean delivery rate with the use of misoprostol, although a recent meta-analysis indicated that the use of intravaginal misoprostol is associated with a lowering of the caesarean rate when compared with pooled controls. Low-dose misoprostol (25 microg) is an effective agent for cervical ripening and labour induction when used in a judicious and cautious fashion. There are insufficient data to support the widespread use of oral misoprostol for cervical ripening and labor induction. Some trials suggest that this approach may be effective; however, the ideal dose and administration regimen have yet to be defined.

Induction of labour with a viable infant: a randomised clinical trial comparing intravaginal misoprostol and intravaginal dinoprostone

OBJECTIVE

To compare the efficacy and safety of vaginal misoprostol (50 microg) with vaginal dinoprostone.

DESIGN

Double-blind randomised trial.

SETTING

Obstetrics Department, Poissy Hospital, France.

PARTICIPANTS

370 patients with medical indications for induction of labour.

OUTCOME MEASURES

Vaginal deliveries within 24 hours, as well as time to vaginal deliveries, caesarean rates, costs, and fetal, neonatal and maternal condition.

RESULTS

Compared with vaginal dinoprostone, vaginal misoprostol resulted in greater efficacy in several areas: vaginal delivery within 24 hours; time to vaginal delivery; and vaginal delivery within 12 hours. There was a non-significant increase in the caesarean section rate for fetal distress in the misoprostol group, but fewer caesarean sections for failed induction. Fetal tolerance was similar in the two groups, although significantly more neonates had a cord pH <7.20 and (non-significantly) none had meconium stained amniotic fluid in the misoprostol group. The incidence of poor neonatal outcome was similar in both groups. Subgroup analysis by indication for induction showed that the higher rates of arterial cord pH <7.20 and of meconium-stained amniotic fluid with misoprostol persisted only in possible fetal compromise. Poor neonatal outcome was less frequent in the misoprostol group in cases of induction for non-fetal indications.

CONCLUSIONS

Vaginal misoprostol resulted in successful and earlier induction of labour more often than dinoprostone, but the safety of misoprostol raises some concern in potentially compromised infants. Misoprostol should be preferred to dinoprostone in cases of induction for non-fetal indications.

Randomized study of vaginal misoprostol (PGE(1)) and dinoprostone gel (PGE(2)) for induction of labor at term

OBJECTIVES

To investigate the efficacy and safety of misoprostol in the induction of labor at term by comparing this agent with the commonly used dinoprostone gel.

PATIENTS AND METHODS

A randomized clinical trial of vaginal misoprostol, 50 microg 6-hourly, and dinoprostone gel, 1-2 mg 6-hourly, in 435 women undergoing induction of labor at term. The women, 210 in the misoprostol group and 225 in the dinoprostone group, were compared to determine whether there was a significant difference in achieving vaginal delivery within 24 h, the incidence of hyperstimulation syndrome, Cesarean section rate and adverse neonatal outcome. They were also offered the option of preinduction sonographic cervical assessment.

RESULTS

Misoprostol, compared to dinoprostone gel, was associated with a significantly shorter median induction-to-delivery interval (14.6 h vs. 19.0 h; P = 0.0014), a higher incidence of vaginal delivery within 24 h of induction (65.7% vs. 54.2%; P = 0.019) and a reduced need for oxytocin augmentation during labor (20.5% vs. 29.8%; P = 0.034). The groups did not differ significantly in the rates of Cesarean section (18.1% vs. 19.1%; P = 0.88) and hyperstimulation syndrome (2.4% vs. 0.9%; P = 0.27). None of the cases of hyperstimulation required treatment with tocolysis. All nine cases of excessive uterine contractility occurred after the first dose of the drug. There were no significant differences in maternal and neonatal morbidity between the two groups. There was a significant association between preinduction cervical length and the induction-to-delivery interval in both those receiving misoprostol and those treated with dinoprostone.

CONCLUSIONS

The use of misoprostol is associated with a shorter duration of labor and a higher rate of vaginal delivery within 24 h from induction without an increase in maternal and neonatal morbidity. Transvaginal sonographic measurement of cervical length is useful in the prediction of the likelihood of vaginal delivery within 24 h of induction and of the induction-to-delivery interval and may be useful in the stratification of patients participating in randomized studies that examine the effectiveness of inducing agents.

A comparison of various routes and dosages of misoprostol for cervical ripening and the induction of labor

OBJECTIVE

The purpose of this study was to compare the efficacy of different routes of misoprostol administration for cervical ripening and the induction of labor.

STUDY DESIGN

Three hundred thirty women at > or = 32 weeks gestation with a Bishop score < or = 6 and an indication for induction were randomized to 1 of 3 double-blinded groups: (1) 25 microg orally administered misoprostol plus 25 microg vaginally administered misoprostol, (2) orally administered placebo plus 25 microg vaginally administered misoprostol, or (3) 25 microg orally administered misoprostol plus vaginally administered placebo. Doses were repeated every 4 hours until onset of labor or a maximum of 12 doses were given. The primary outcome of the trial was vaginal delivery within 24 hours of the initiation of induction. Secondary outcomes were the time from induction to delivery, need for oxytocin augmentation, mode of delivery, frequency of side effects, and neonatal and maternal outcome. Analysis of variance, chi-square test, and logistic regression were used for analysis.

RESULTS

There were no significant differences in maternal characteristics or indications for induction. The percentage of women who achieved vaginal delivery within 24 hours was highest in the vaginally administered misoprostol group: 67% compared with 53% in the oral-plus-vaginal group (P < .05) and 36% in the oral group (P < .05). The median time to vaginal delivery was shorter in the vaginal and oral-plus-vaginal misoprostol groups, 13.5 hours and 14.3 hours, respectively, when compared with 23.9 hours in the oral group (P < .05). The rate of cesarean delivery was lowest in the vaginal misoprostol group (17% compared with 30% in the oral-plus-vaginal group and 32% in the oral group; P < .05). Uterine tachysystole occurred least frequently in the oral misoprostol group (10% compared with 32% in the vaginal group and 34% in the oral-plus-vaginal group; P < .05). Uterine hyperstimulation also occurred least frequently in the oral misopro-stol group (4% compared with 15% in the vaginal group and 22% in the oral-plus-vaginal group; P < .05).

CONCLUSION

At the doses studied, induction of labor with vaginally administered misoprostol is more efficacious than either oral-plus-vaginal or oral-only route of administration.

Myomectomy during the first trimester associated with fetal limb anomalies and hydrocephalus in a twin pregnancy

OBJECTIVES

To present the complications of a twin pregnancy after first trimester myomectomy and to discuss the possible etiologic relationship.

CASE REPORT

A 44-year-old primigravida with a dichorionic-diamniotic twin pregnancy underwent myomectomy in another hospital at 12 weeks' gestational age. At 28 weeks the patient was referred to our unit because of ventriculomegaly and limb anomalies in the second twin. The patient underwent a Caesarean section at 37 weeks of gestation delivering twin A, a healthy female weighing 3235 g and twin B, a female weighing 2810 g with hydrocephalus and limb anomalies (clubfeet and hypoplasia of the nails and terminal phalanges). The placenta from twin A was normal, but in the placenta of twin B haemorrhage, thrombosis and infarction were noted.

CONCLUSIONS

Despite several reports of myomectomy in pregnancy without any problems for mother and fetus, the authors believe that myomectomy - especially in the first trimester - may be associated with the type of problems observed in the present case. The pathophysiological relationship between placental trauma and haemodynamic alterations as a possible cause of the malformations in twin B is discussed.

Misoprostol versus dinoprostone for cervical priming prior to induction of labour in term pregnancy: a randomised controlled trial

A prospective randomised controlled trial was performed to compare the efficacy and safety of intravaginal misoprostol to that of intravaginal dinoprostone when used for cervical priming prior to the induction of labour; 126 women were recruited to the study and randomised to receive either intravaginal dinoprostone (n = 63) or misoprostol (n = 63) for cervical priming prior to induction of labour. The mean time from insertion of the priming agent to vaginal delivery was significantly shorter in the misoprostol group (925.8 versus 1577.6 minutes), the mean duration of the active length of labour was significantly shorter in the misoprostol group (353.7 versus 496.8 minutes) and more women in the misoprostol group delivered in less than 12 hours (92% versus 76.5%). Women in the misoprostol group were less likely to require a repeated dose of prostaglandin for cervical priming and less likely to require oxytocin for augmentation of labour. There was no difference in the number of women who were delivered vaginally or by Ceasarean section between the two groups. More women developed hyperstimulation during labour in the misoprostol group; however there was no difference between the groups in neonatal outcome in respect to low cord pH or Apgar score at delivery or admission to the neonatal special care nursery.

A comparison of oral and vaginal misoprostol for induction of labour at term: a randomised trial

OBJECTIVE

To compare the efficacy of oral with vaginal misoprostol for induction of labour at term.

DESIGN

Randomised trial.

SETTING

Tertiary Care hospital.

PARTICIPANTS

One hundred and sixty-seven women requiring induction of labour.

METHODS

The women were randomised to receive 50 microg of misoprostol orally or vaginally every 6 h until the cervix was favourable for amniotomy, spontaneous rupture of membranes, or active labour occurred. Sample size was calculated with a two-tailed alpha of 0.05 and a power of 95% to detect a 5 h difference in induction-to-delivery time. Student's t test was used for comparison of normally distributed continuous variables and the Mann-Whitney U test was used for non-Gaussian distributed continuous variables. Fisher' s exact and chi2 tests were used for comparison of categorical variables. The main outcome measure was induction to delivery time.

RESULTS

The median induction to delivery time was significantly shorter with vaginal misoprostol (15.7 h range 4.3-55.7), compared with oral misoprostol (23.0 h range 3.2-141.7, P = 0.0013). The median number of doses was also significantly less in the vaginal misoprostol group, 1 (range 1-3), compared with the oral group, 2 (range 1-8), (P < 0.0001). The significant differences in outcome held true when nulliparous and multiparous women were analysed separately. There were no differences between the two routes of administration with respect to rates of hyperstimulation or neonatal asphyxia. There were more caesarean sections in the vaginal misoprostol group, but the difference was not statistically significant.

CONCLUSIONS

Compared with oral misoprostol, vaginal misoprostol for induction of labour at term results in a shorter induction-to-delivery time, with fewer doses required per patient. Vaginal misoprostol may be associated with higher rates of caesarean section than oral misoprostol.

A randomized trial of misoprostol versus extra-amniotic sodium chloride infusion with oxytocin for induction of labor

OBJECTIVE

Our purpose was to compare the efficacy and safety of misoprostol and extra-amniotic sodium chloride infusion with oxytocin for induction of labor.

STUDY DESIGN

This randomized trial compared two methods of labor induction in women requiring cervical ripening. One hundred twenty-three women undergoing labor induction with a Bishop score < or =5 were randomly selected to receive either misoprostol, 50 microg intravaginally every 4 hours, or extra-amniotic sodium chloride infusion. The primary outcome variable was the time interval from induction to vaginal delivery.

RESULTS

Sixty-one women received extra-amniotic sodium chloride infusion and 62 women received misoprostol. The mean time interval from the start of induction to vaginal delivery was 15.0 +/- 5.0 hours and 16.5 +/- 7.2 hours for the extra-amniotic infusion and misoprostol groups, respectively (P, not significant). The cesarean delivery rate was not significantly different between the 2 groups (32.8% for the extra-amniotic infusion group; 19.4% for the misoprostol group). Maternal and neonatal outcomes were similar between the 2 groups.

CONCLUSIONS

Both methods of induction are equally efficacious and result in similar maternal and neonatal outcomes.

Uterine and fetal Doppler flow changes after misoprostol and oxytocin therapy for induction of labor in post-term pregnancies

OBJECTIVES

To compare the effect of misoprostol vs. oxytocin on blood flow in uteroplacental circulation during labor induction.

METHODS

Ninety-one women with indications for induction of labor were assigned to receive either misoprostol 50 microg per vagina every 4 h as needed or intravenous oxytocin by means of a randomization table generated by computer. Doppler velocimetry of umbilical, uterine and arcuate arteries was performed immediately before and 2-3 h after administration of misoprostol or oxytocin. Pulsatility index (PI), resistance index (RI) and systolic/diastolic (S/D) ratios were measured for these arteries. The SAS system was used to perform statistical analysis.

RESULTS

There were no significant changes of PI, RI and S/D ratios in umbilical arteries during misoprostol and oxytocin inductions. Vaginal application of misoprostol significantly increased PI, RI and S/D ratios in arcuate arteries and S/D ratio in uterine arteries.

CONCLUSIONS

Our results indicate that intravaginal misoprostol administration increases uteroplacental resistance but probably does not substantially affect placental perfusion.

Randomized comparison between intravaginal misoprostol and dinoprostone for cervical ripening and induction of labor

OBJECTIVE

We sought to evaluate the efficacy and safety of intravaginal misoprostol and dinoprostone for labor induction.

STUDY DESIGN

One hundred eighty-nine women with singleton term pregnancies and unfavorable cervices were randomly assigned to receive intravaginal misoprostol or dinoprostone. The outcome variables were change in Bishop score, time from application to active phase of labor and delivery, fetal and maternal morbidity, and the incidence of cesarean deliveries.

RESULTS

The interval from application of the initial dose to the beginning of the active phase of labor was 9.8 +/- 5.8 and 14.2 +/- 10.2 hours (P <.01), and the interval from initial dose to delivery was 15.3 +/- 9.8 and 19.1 +/- 13.2 hours (P =.027) for the misoprostol and dinoprostone groups, respectively. There were no significant differences in Bishop score change, cesarean delivery rate, and the incidence of tachysystole, hypersystole, and hyperstimulation. No maternal and neonatal adverse effects were noted.

CONCLUSION

Intravaginal misoprostol is more effective than intravaginal dinoprostone for labor induction in low-risk patients at term with unfavorable cervices.

Labor induction with misoprostol

Misoprostol, a prostaglandin E(1 ) analog, is widely used in the United States for cervical ripening and labor induction. Its use for these indications is not approved by the US Food and Drug Administration. The only Food and Drug Administration-approved indication in the product labeling is the treatment and prevention of intestinal ulcer disease resulting from nonsteroidal anti-inflammatory use. Multiple trials have proved that misoprostol is an effective agent for cervical ripening and labor induction in term pregnancy; however, investigations continue regarding the optimal dose, dosing regimen, and route of administration. Uterine contraction abnormalities are often found in association with higher misoprostol doses. Some trials also indicate increased frequencies of meconium passage, neonatal acidemia, and cesarean delivery for fetal distress in women receiving higher doses of misoprostol. Overall, most trials fail to demonstrate a significant change in the cesarean delivery rate with the use of this agent. Misoprostol is an effective agent for cervical ripening and labor induction when used in a judicious and cautious fashion.

Misoprostol is more efficacious for labor induction than prostaglandin E2, but is it associated with more risk?

OBJECTIVE

Our purpose was to compare the efficacy and safety of misoprostol with dinoprostone (Prepidil) for labor induction.

STUDY DESIGN

In a randomized, controlled trial of labor induction, patients were randomly assigned to receive either 50 microgram of intravaginal misoprostol every 4 hours or 0.5 mg of intracervical prostaglandin E2 every 6 hours. Eligibility criteria included gestation of >/=31 weeks, Bishop score <6, and fewer than 12 contractions per hour. Primary outcomes were cesarean section, induction to delivery time, oxytocin use, and fetal distress requiring delivery.

RESULTS

One hundred fifty-nine women were randomly assigned to receive misoprostol (n = 81) or Prepidil (n = 78). There were no differences in the indication for induction, preinduction Bishop score, epidural use, or cesarean section rate. Mean time to delivery was significantly shorter in the misoprostol group (19 hours 50 minutes) than in the Prepidil group (28 hours 52 minutes) (P =.005). Only 58% of women in the misoprostol group required oxytocin augmentation, in comparison with 88% of women receiving Prepidil (P =.00002). However, 41% of women receiving misoprostol and 17% receiving Prepidil had late decelerations or bradycardias (P =.001), and 20% of the misoprostol group and 5% of the Prepidil group had deliveries for fetal distress (P =.05).

CONCLUSIONS

Misoprostol is more efficacious than Prepidil for labor induction. However, the significantly increased incidence of abnormal fetal heart rate tracings and the trend in increased deliveries for fetal distress with misoprostol dosing of 50 microgram every 4 hours are of concern. These data suggest that either a lower dose of misoprostol or less frequent dosing of misoprostol should be considered.

Comparison of the safety and efficacy of intravaginal misoprostol (prostaglandin E1) with those of dinoprostone (prostaglandin E2) for cervical ripening and induction of labor in a community hospital

OBJECTIVE

This clinical trial evaluated the efficacy of intravaginal misoprostol (prostaglandin E1) and compared it with that of dinoprostone (prostaglandin E2) for cervical ripening and induction of labor in a community hospital.

STUDY DESIGN

This study involved a retrospective analysis of 81 patients undergoing cervical ripening and induction of labor with prostaglandin E2 from May 1, 1996, to May 1, 1997. A comparison prospective analysis of 145 patients undergoing the same procedure with prostaglandin E1 from May 1, 1997 to May 1, 1998, was performed.

RESULTS

The mean time to delivery was significantly shorter with misoprostol (19.8 +/- 10.4 hours) than with prostaglandin E2 (31.3 +/- 13.0 hours, P <.001). Delivery within 24 hours of induction was significantly more frequent with misoprostol (71.9% of subjects vs 31.3%, P <.001). There was no difference in the cesarean delivery rate with misoprostol (25.6% vs 22.2%, P <.67). The incidence of uterine hyperstimulation was higher with prostaglandin E2 (7.4% vs 0.7%, P <.007). There were no uterine ruptures with prostaglandin E2. There were 2 uterine ruptures and 1 dehiscence with prostaglandin E1 in 3 patients with previous cesarean deliveries and 1 rupture in a patient without a history of uterine scarring. There was no difference in neonatal outcome, with the exception of a fetal death related to uterine rupture in the misoprostol group.

CONCLUSIONS

Compared with prostaglandin E2, misoprostol is more effective in cervical ripening and induction of labor, is as safe for patients who do not have a history of cesarean birth, may carry a higher incidence of uterine rupture, and should not be used for patients attempting vaginal birth after previous cesarean delivery.

Regional variations in contractile responses to prostaglandins and prostanoid receptor messenger ribonucleic acid in pregnant baboon uterus

OBJECTIVES

The aims of this study were to compare (1) the contractile responses of the lower uterine segment and fundus to prostaglandins, (2) expression of genes encoding prostanoid receptors in myo-metrium from different regions of the uterus, and (3) the distribution of expression of genes encoding prostanoid receptors (P receptors) in key intrauterine tissues.

STUDY DESIGN

Cesarean hysterectomy was performed in 8 pregnant baboons, not in labor, in the last third of pregnancy. Contractile responses of fresh tissue were quantified in a superfusion system. Polyadenylated ribonucleic acid was extracted from frozen tissue and gene expression was quantified by Northern blot analysis with complementary deoxyribonucleic acid probes.

RESULTS

Prostaglandin E2 contracted strips of myometrium from the fundus but had no significant effect on strips from lower uterine segment. Prostaglandin F2 alpha contracted myometrium from both regions equally. Compared with fundus tissue, lower uterine segment tissue had greater expression of EP2 receptor messenger ribonucleic acid, less expression of EP3 receptor messenger ribonucleic acid, but similar levels of EP4 receptor and FP receptor messenger ribonucleic acid. EP2 receptor, EP3 receptor, and EP4 receptor messenger ribonucleic acids were also detected in cervix, decidua, and chorion. EP2 receptor messenger ribonucleic acid was most abundant in the cervix, EP3 receptor messenger ribonucleic acid was most abundant in the myometrium, and EP4 receptor messenger ribonucleic acid was most abundant in the decidua.

CONCLUSIONS

The reduced contractile response of lower uterine segment tissue to prostaglandin E2 is paralleled by greater inhibitory EP2 receptor expression and less contractile EP3 receptor expression, a pattern similar to that seen in the cervix. Drugs with selective activity at prostanoid receptor types and subtypes are likely to allow safer and more effective control of the uterus and cervix than native prostaglandins.

Medication use during the perinatal period

OBJECTIVE

To briefly describe the drug therapy administered during the perinatal period of pregnancy for common maternal and fetal complications, and to identify those agents that should not be used for these conditions.

DATA SOURCES

References were obtained from an ongoing literature search of peer-reviewed obstetric and gynecologic journals and other selected medical and pharmacy journals available in the English language. Primary search vehicle was a weekly review of the tables of contents of nearly 1,300 medical journals provided by Reference Update (Institute of Scientific Information, Philadelphia). MEDLINE searches were also conducted using key terms for each subtopic.

STUDY SELECTION

Specific references were selected for each topic based on the adequacy of their study design, patient population, and a recent publication date. Reviews were used if a large number of primary references would have been required to adequately describe the topic.

DATA EXTRACTION

Most references reflected the current opinions expressed in the Educational (Technical) Bulletin and Committee Opinion series published by the American College of Obstetricians and Gynecologists. Recent, well-conducted studies that arrived at different conclusions were also included.

DATA SYNTHESIS

Data obtained from each reference reflected the conclusions of the authors based on their research or an analysis of the research on others on the appropriate use of the drug(s) for the specific condition being treated.

CONCLUSION

Drug therapy during the perinatal period is frequently required and can be beneficial for the mother, fetus, and newborn. Many complications previously associated with severe morbidity and mortality, such as infections, premature rupture of membranes, preterm labor, hypertension, maternal pain during labor, and postpartum hemorrhage, are now controlled with appropriate pharmacologic therapy. All health professionals who provide services to pregnant women should be knowledgeable in this drug therapy.