A comparison of orally administered misoprostol with vaginally administered misoprostol for cervical ripening and labor induction

Efficacy and safety of oral versus vaginal misoprostol for medical management of first trimester missed abortion: A systematic review and meta-analysis

BACKGROUND

Missed abortion in the first trimester is characterized by the cessation of embryonic or fetal development while the cervix remains closed, often resulting in little to no bleeding. Ultrasound examinations typically reveal an empty gestational sac or an embryo/fetus that lacks cardiac activity. Misoprostol is the primary medication used to manage early pregnancy loss.

OBJECTIVES

To compare the efficacy of misoprostol, orally and vaginally in management of first trimester missed abortion."

STUDY SELECTION

This systematic review included randomised control trials of patients with a confirmed diagnosis with first-trimester missed abortion, comparing oral and vaginal misoprostol for uterine evacuation success, induction-expulsion time, patient satisfaction and adverse events.

DATA EXTRACTION AND ANALYSIS

Ten studies were included in this meta-analysis. All of them are RCTs with a number of patients 1,142 [578 in oral misoprostol group and 564 in vaginal misoprostol group]. Independent data extraction and quality assessment ensured unbiased results. We estimated risk ratios (RR) with 95% CIs using random-effects meta-analysis and evaluated quality of the included studies using Cochrane's Risk of Bias tool (RoB 2).

RESULTS

We included 10 studies in our analysis and for our primary outcome, vaginal misoprostol had a higher success rate, [RR: 0.85, P = 0.004], shorter induction-expulsion interval [MD:4.95, P = 0.0001], and greater patient satisfaction compared to oral administration [RR:0.85, P = 0.01]. Secondary outcomes revealed significantly higher nausea and vomiting in the oral group, with no significant difference in headache, dizziness, diarrhea, fever, excessive bleeding, or discharge. Severe crampy pain was also significantly higher in the oral group.

CONCLUSION

Our comprehensive review and meta-analysis indicate that the vaginal route of misoprostol is the most effective method for managing first-trimester missed abortions. This route achieves a significantly higher success rate and shorter induction- to-expulsion interval, along with greater patient satisfaction during follow-up sessions and fewer side effects.

The efficacy and safety of 25 μg or 50 μg oral misoprostol versus 25 μg vaginal misoprostol given at 4- or 6-hourly intervals for induction of labour in women at or beyond term with live singleton pregnancies: A systematic review and meta-analysis

BACKGROUND

Misoprostol is widely used for cervical ripening and labour induction as it is heat-stable and inexpensive. Oral misoprostol 25 μg given 2-hourly is recommended over vaginal misoprostol 25 μg given 6-hourly, but the need for 2-hourly fetal monitoring makes oral misoprostol impractical for routine use in high-volume obstetric units in resource-constrained settings.

OBJECTIVES

To compare the efficacy and safety of oral misoprostol initiated at 25 or 50 μg versus 25 μg vaginal misoprostol given at 4- to 6-hourly intervals for labor induction in women at or beyond term (≥ 37 weeks) with a single viable fetus and an unscarred uterus.

SEARCH STRATEGY

We identified eligible randomized, parallel-group, labor-induction trials from recent systematic reviews. We additionally searched PubMed, Cochrane CENTRAL, Epistemonikos, and clinical trials registries from February 1, 2020 to December 31, 2022 without language restrictions. Database-specific keywords for cervical priming, labor induction, and misoprostol were used.

SELECTION CRITERIA

We excluded labor-induction trials exclusively in women with ruptured membranes, in the third trimester, and those that initiated misoprostol at doses not specified in the review's objectives. The primary outcomes were vaginal birth within 24 h, cesarean section, perinatal mortality, neonatal morbidity, and maternal morbidity. The secondary outcomes were uterine hyperstimulation with fetal heart rate changes, and oxytocin augmentation.

DATA COLLECTION AND ANALYSIS

Two or more authors selected studies independently, assessed risk of bias, and extracted data. We derived pooled weighted risk ratios with 95% confidence intervals (CIs) for each outcome, subgrouping trials by the dose and frequency of misoprostol regimens. We used the I2 statistic to quantify heterogeneity and the random-effects model for meta-analysis when appropriate. We used the Grades of Recommendation, Assessment, Development and Evaluation (GRADE) approach to assess certainty (confidence) in the effect estimates.

MAIN RESULTS

Thirteen trials, from Canada, India, Iran, and the US, randomizing 2941 women at ≥37 weeks of gestation with an unfavorable cervix (Bishop score <6), met the eligibility criteria. Five misoprostol regimens were compared: 25 μg oral versus 25 μg vaginal, 4-hourly (three trials); 50 μg oral versus 25 μg vaginal, 4-hourly (five trials); 50 μg followed by 100 μg oral versus 25 μg vaginal, 4-hourly (two trials); 50 μg oral, 4-hourly versus 25 μg vaginal, 6-hourly (one trial); and 50 μg oral versus 25 μg vaginal, 6-hourly (two trials). The overall certainty in the evidence ranged from moderate to very low, due to high risk of bias in 11/13 trials (affecting all outcomes), unexplained heterogeneity (1/7 outcomes), indirectness (1/7 outcomes), and imprecision (4/7 outcomes). Vaginal misoprostol probably increased vaginal deliveries within 24 h compared with oral misoprostol (risk ratio [RR] 0.82, 95% CI 0.70-0.96; 11 trials, 2721 mothers; moderate-certainty evidence); this was more likely with 4-hourly than with 6-hourly vaginal regimens. The risk of cesarean sections did not appreciably differ (RR 1.00, 95% CI 0.80-1.26; 13 trials, 2941 mothers; very low-certainty evidence), although oral misoprostol 25 μg 4-hourly probably increased this risk compared with 25 μg vaginal misoprostol 4-hourly (RR 1.69, 95% CI 1.21-2.36; three trials, 515 mothers). The risk of perinatal mortality (RR 0.67, 95% CI 0.11-3.90; one trial, 196 participants; very low-certainty evidence), neonatal morbidity (RR 0.84, 95% CI 0.67-1.06; 13 trials, 2941 mothers; low-certainty evidence), and maternal morbidity (RR 0.83, 95% CI 0.48-1.44; 6 trials; 1945 mothers; moderate-certainty evidence) did not differ appreciably. The risk of uterine hyperstimulation with fetal heart rate changes may be lower with oral misoprostol (RR 0.70, 95% CI 0.52-0.95; 10 trials, 2565 mothers; low-certainty evidence). Oxytocin augmentation was probably more frequent with oral compared with vaginal misoprostol (RR 1.29, 95% CI 1.10-1.51; 13 trials, 2941 mothers; moderate-certainty evidence).

CONCLUSIONS

Low-dose, 4- to 6-hourly vaginal misoprostol regimens probably result in more vaginal births within 24 h and less frequent oxytocin use compared with low-dose, 4- to 6-hourly, oral misoprostol regimens. Vaginal misoprostol may increase the risk of uterine hyperstimulation with fetal heart changes compared with oral misoprostol, without increasing the risk of perinatal mortality, neonatal morbidity, or maternal morbidity. Indirect evidence indicates that 25 μg vaginal misoprostol 4-hourly may be more effective and as safe as the recommended 6-hourly vaginal regimen. This evidence could inform clinical decisions in high-volume obstetric units in resource-constrained settings.

Vaginal Compared With Oral Misoprostol Induction at Term: A Cluster Randomized Controlled Trial

OBJECTIVE

To evaluate efficacy in achieving vaginal delivery with a standardized vaginal compared with oral misoprostol regimen for labor induction at term.

METHODS

In this single-center, cluster randomized trial, we randomized induction method by week among individuals with gestational age of 37 weeks or more, cervical dilation of 2 cm or less, intact membranes, and indication for delivery to either oral (100 micrograms every 4 hours for up to two doses), or vaginal (25 micrograms every 3 hours for up to five doses) misoprostol regimens, followed by a standardized oxytocin protocol. Individuals with an antepartum stillbirth, major fetal anomalies, malpresentation, ruptured membranes, nonreassuring fetal status, or contraindication to prostaglandin were excluded. The primary outcome was vaginal delivery at first induction attempt. Secondary outcomes included time to delivery, need for oxytocin, chorioamnionitis, and adverse maternal and neonatal outcomes. Outcomes were recorded at the individual level and adjusted for clustering, with analysis by intention to treat.

RESULTS

Between May 24, 2021, to September 19, 2022, 1,322 women were randomized to vaginal misoprostol in 33 clusters and 1,224 to oral misoprostol in 37 clusters. Demographic characteristics or initial cervical dilation did not differ between groups. The primary outcome did not differ between induction regimens and occurred in 1,032 (78.1%) of the vaginal misoprostol arm and 945 (77.2%) of the oral misoprostol arm (adjusted relative risk [RR] 1.01, 95% CI, 0.97-1.05). Tachysystole with fetal heart rate changes occurred less frequently with vaginal compared with oral misoprostol (3.5% vs 5.9%, adjusted RR 0.59, 95% CI, 0.40-0.87). Time to delivery did not differ between groups. Oxytocin was less frequently required before delivery in the vaginal misoprostol group (68.8% vs 78.4%, adjusted RR 0.88, 95% CI, 0.84-0.92).

CONCLUSION

Induction of labor with vaginal compared with oral misoprostol protocols did not increase the frequency of vaginal delivery at term but did reduce the need for oxytocin use before delivery.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, NCT04755218.

Safety and efficacy of double-balloon catheter for cervical ripening: a Bayesian network meta-analysis of randomized controlled trials

BACKGROUND

Various methods are used for cervical ripening during the induction of labor. Mechanical and pharmacological methods are commonly used for cervical ripening. A double-balloon catheter was specifically developed to ripen the cervix and induce labor; however, the efficacy of the double-balloon catheter in cervical ripening compared to other methods is unknown.

METHODS

We searched five databases and performed a Bayesian network meta-analysis. Six interventions (double-balloon catheter, Foley catheter, oral misoprostol, vaginal misoprostol, dinoprostone, and double-balloon catheter combined with oral misoprostol) were included in the search. The primary outcomes were cesarean delivery rate and time from intervention-to-birth. The secondary outcomes were as follows: Bishop score increment; achieving a vaginal delivery within 24 h; uterine hyperstimulation with fetal heart rate changes; need for oxytocin augmentation; instrumental delivery; meconium staining; chorioamnionitis; postpartum hemorrhage; low Apgar score; neonatal intensive care unit admission; and arterial pH.

RESULTS

Forty-eight randomized controlled trials involving 11,482 pregnant women were identified. The cesarean delivery rates of the cervical ripening with a double-balloon catheter and oral misoprostol, oral misoprostol, and vaginal misoprostol were significantly lower than cervical ripening with a Foley catheter (OR = 0.48, 95% CI: 0.23-0.96; OR = 0.74, 95% CI: 0.58-0.93; and OR = 0.79, 95% CI: 0.64-0.97, respectively; all P < 0.05). The time from intervention-to-birth of vaginal misoprostol was significantly shorter than the other five cervical ripening methods. Vaginal misoprostol and oral misoprostol increased the risk of uterine hyperstimulation with fetal heart rate changes compared to a Foley catheter. A double-balloon catheter with or without oral misoprostol had similar outcomes, including uterine hyperstimulation with fetal heart rate changes compared to a Foley catheter.

CONCLUSION

Double-balloon catheter did not show superiority when compared with other single method in primary and secondary outcomes of labor induction. The combination of double-balloon catheter with oral misoprostol was significantly reduced the rate of cesarean section compared to Foley catheter without increased risk of uterine hyperstimulation with fetal heart rate changes, which was shown in oral or vaginal misoprostol.

Induction of labor at term with vaginal misoprostol or a prostaglandin E2 pessary: a noninferiority randomized controlled trial

BACKGROUND

Induction of labor is among the most common procedures for pregnant women. Only a few randomized clinical trials with relatively small samples have compared misoprostol with dinoprostone. Although their efficacy seems similar, their safety profiles have not been adequately evaluated, and economic data are sparse.

OBJECTIVE

This study aimed to test the noninferiority of vaginal misoprostol (prostaglandin E1) (25 μg) to a slow-release dinoprostone (prostaglandin E2) pessary (10 μg) for induction of labor with an unfavorable cervix at term.

STUDY DESIGN

This was an open-label multicenter randomized noninferiority trial at 4 university hospitals of the Research Group in Obstetrics and Gynecology between 2012 and 2015. We recruited women who underwent induction of labor for medical reasons, those with a Bishop score of ≤5 at ≥36 weeks' gestation, and those with a cephalic-presenting singleton pregnancy with no previous cesarean delivery. Women were randomly allocated to receive either vaginal misoprostol at 4-hour intervals (25 μg) or a 10-mg slow-release dinoprostone pessary. The primary outcome was the total cesarean delivery rate. Noninferiority was defined as a difference in the cesarean delivery rates between the groups of no more than 5%. Secondary outcomes included neonatal and maternal morbidity, vaginal delivery at <24 hours after starting the induction of labor process, and maternal satisfaction.

RESULTS

The study included 1674 randomized women. The per-protocol analysis included 790 women in each group. The total cesarean delivery rates were 22.1% (n=175) in the misoprostol group and 19.9% (n=157) in the dinoprostone group, a difference of 2.2% (with an upper-bound 95% confidence limit of 5.6%) (P=.092). Results in the intention-to-treat analysis were similar. Neonatal and maternal morbidity rates were similar between groups. Vaginal delivery within 24 hours was significantly higher in the misoprostol group (59.3% vs 45.7%; P<.001) as was maternal satisfaction, assessed in the postpartum period by a visual analog scale (mean score, 7.1±2.4 vs 5.8±3.1; P<.001).

CONCLUSION

The noninferiority of a 25-μg dose of vaginal misoprostol every 4 hours to the dinoprostone pessary for cesarean delivery rates after induction of labor at term could not be demonstrated, although the confidence limit of the difference barely exceeded the noninferiority margin. Nonetheless, given the small difference between these cesarean delivery rates and the similarity of neonatal and maternal morbidity rates in this large study, the clinical risk-to-benefit ratio justifies the use of both drugs.

Cost-effectiveness analysis of vaginal misoprostol versus dinoprostone pessary: A non-inferiority large randomized controlled trial in France

OBJECTIVE

To assess the cost-effectiveness of vaginal misoprostol (PGE1; 25 μg) compared with a slow-release dinoprostone (PGE2) pessary (10 μg) for labor induction due to an unfavorable cervix at term.

METHODS

We used data from an open-label multicenter, randomized non-inferiority trial that recruited women for whom labor was induced for medical reasons. The incremental cost-effectiveness ratio was assessed from the payer's perspective, with the focus on inpatient care costs and using the cesarean deliveries avoided (CDA) rate as the primary analysis and the rate of vaginal delivery within 24 h (VD24) as the secondary analysis.

RESULTS

Analyses were based on 790 women in each group. Differences between treatment arms were the mean cost per patient of €4410 and €4399, a CDA rate of 80.1% and 77.9% and a VD24 rate of 46.1% and 59.4% for dinoprostone and misoprostol, respectively. Dinoprostone is not cost-effective according to the CDA rate and misoprostol was either a cost-effective or a dominant strategy according to the VD24.

CONCLUSION

Misoprostol and dinoprostone have equal cost management with mixed efficacy according to the clinical outcome used. Finally, misoprostol may be an attractive option for hospitals as the price is lower and it is easier to use.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01765881. URL: https://clinicaltrials.gov/ct2/show/NCT01765881. ClinicalTrialRegistrer.eu: 2011-000933-35. URL: https://www.clinicaltrialsregister.eu/ctr-search/trial/2011-000933-35/FR.

Low-dose oral misoprostol for induction of labour

BACKGROUND

Misoprostol given orally is a commonly used labour induction method. Our Cochrane Review is restricted to studies with low-dose misoprostol (initially ≤ 50 µg), as higher doses pose unacceptably high risks of uterine hyperstimulation.

OBJECTIVES

To assess the efficacy and safety of low-dose oral misoprostol for labour induction in women with a viable fetus in the third trimester of pregnancy.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov,  the WHO International Clinical Trials Registry Platform (14 February 2021) and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised trials comparing low-dose oral misoprostol (initial dose ≤ 50 µg) versus placebo, vaginal dinoprostone, vaginal misoprostol, oxytocin, or mechanical methods; or comparing oral misoprostol protocols (one- to two-hourly versus four- to six-hourly; 20 µg to 25 µg versus 50 µg; or 20 µg hourly titrated versus 25 µg two-hourly static).

DATA COLLECTION AND ANALYSIS

Using Covidence, two review authors independently screened reports, extracted trial data, and performed quality assessments. Our primary outcomes were vaginal birth within 24 hours, caesarean section, and hyperstimulation with foetal heart changes.

MAIN RESULTS

We included 61 trials involving 20,026 women. GRADE assessments ranged from moderate- to very low-certainty evidence, with downgrading decisions based on imprecision, inconsistency, and study limitations. Oral misoprostol versus placebo/no treatment (four trials; 594 women) Oral misoprostol may make little to no difference in the rate of caesarean section (risk ratio (RR) 0.81, 95% confidence interval (CI) 0.59 to 1.11; 4 trials; 594 women; moderate-certainty evidence), while its effect on uterine hyperstimulation with foetal heart rate changes is uncertain (RR 5.15, 95% CI 0.25 to 105.31; 3 trials; 495 women; very low-certainty evidence). Vaginal births within 24 hours was not reported. In all trials, oxytocin could be commenced after 12 to 24 hours and all women had pre-labour ruptured membranes. Oral misoprostol versus vaginal dinoprostone (13 trials; 9676 women) Oral misoprostol probably results in fewer caesarean sections (RR 0.84, 95% CI 0.78 to 0.90; 13 trials, 9676 women; moderate-certainty evidence). Subgroup analysis indicated that 10 µg to 25 µg (RR 0.80, 95% CI 0.74 to 0.87; 9 trials; 8652 women) may differ from 50 µg (RR 1.10, 95% CI 0.91 to 1.34; 4 trials; 1024 women) for caesarean section. Oral misoprostol may decrease vaginal births within 24 hours (RR 0.93, 95% CI 0.87 to 1.00; 10 trials; 8983 women; low-certainty evidence) and hyperstimulation with foetal heart rate changes (RR 0.49, 95% CI 0.40 to 0.59; 11 trials; 9084 women; low-certainty evidence). Oral misoprostol versus vaginal misoprostol (33 trials; 6110 women) Oral use may result in fewer vaginal births within 24 hours (average RR 0.81, 95% CI 0.68 to 0.95; 16 trials, 3451 women; low-certainty evidence), and less hyperstimulation with foetal heart rate changes (RR 0.69, 95% CI 0.53 to 0.92, 25 trials, 4857 women, low-certainty evidence), with subgroup analysis suggesting that 10 µg to 25 µg orally (RR 0.28, 95% CI 0.14 to 0.57; 6 trials, 957 women) may be superior to 50 µg orally (RR 0.82, 95% CI 0.61 to 1.11; 19 trials; 3900 women). Oral misoprostol probably does not increase caesarean sections overall (average RR 1.00, 95% CI 0.86 to 1.16; 32 trials; 5914 women; low-certainty evidence) but likely results in fewer caesareans for foetal distress (RR 0.74, 95% CI 0.55 to 0.99; 24 trials, 4775 women). Oral misoprostol versus intravenous oxytocin (6 trials; 737 women, 200 with ruptured membranes) Misoprostol may make little or no difference to vaginal births within 24 hours (RR 1.12, 95% CI 0.95 to 1.33; 3 trials; 466 women; low-certainty evidence), but probably results in fewer caesarean sections (RR 0.67, 95% CI 0.50 to 0.90; 6 trials; 737 women; moderate-certainty evidence). The effect on hyperstimulation with foetal heart rate changes is uncertain (RR 0.66, 95% CI 0.19 to 2.26; 3 trials, 331 women; very low-certainty evidence). Oral misoprostol versus mechanical methods (6 trials; 2993 women) Six trials compared oral misoprostol to transcervical Foley catheter. Misoprostol may increase vaginal birth within 24 hours (RR 1.32, 95% CI 0.98 to 1.79; 4 trials; 1044 women; low-certainty evidence), and probably reduces the risk of caesarean section (RR 0.84, 95% CI 0.75 to 0.95; 6 trials; 2993 women; moderate-certainty evidence). There may be little or no difference in hyperstimulation with foetal heart rate changes (RR 1.31, 95% CI 0.78 to 2.21; 4 trials; 2828 women; low-certainty evidence). Oral misoprostol one- to two-hourly versus four- to six-hourly (1 trial; 64 women) The evidence on hourly titration was very uncertain due to the low numbers reported. Oral misoprostol 20 µg hourly titrated versus 25 µg two-hourly static (2 trials; 296 women) The difference in regimen may have little or no effect on the rate of vaginal births in 24 hours (RR 0.97, 95% CI 0.80 to 1.16; low-certainty evidence). The evidence is of very low certainty for all other reported outcomes.

AUTHORS' CONCLUSIONS

Low-dose oral misoprostol is probably associated with fewer caesarean sections (and therefore more vaginal births) than vaginal dinoprostone, and lower rates of hyperstimulation with foetal heart rate changes. However, time to birth may be increased, as seen by a reduced number of vaginal births within 24 hours. Compared to transcervical Foley catheter, low-dose oral misoprostol is associated with fewer caesarean sections, but equivalent rates of hyperstimulation. Low-dose misoprostol given orally rather than vaginally is probably associated with similar rates of vaginal birth, although rates may be lower within the first 24 hours. However, there is likely less hyperstimulation with foetal heart changes, and fewer caesarean sections performed due to foetal distress. The best available evidence suggests that low-dose oral misoprostol probably has many benefits over other methods for labour induction. This review supports the use of low-dose oral misoprostol for induction of labour, and demonstrates the lower risks of hyperstimulation than when misoprostol is given vaginally. More trials are needed to establish the optimum oral misoprostol regimen, but these findings suggest that a starting dose of 25 µg may offer a good balance of efficacy and safety.

Oral or Vaginal Misoprostol for Labor Induction and Cesarean Delivery Risk

OBJECTIVE

To evaluate whether cervical ripening with oral misoprostol increases cesarean delivery risk and prolongs time to vaginal delivery compared with vaginal misoprostol in a predominantly overweight population.

METHODS

This single center, retrospective cohort study was performed at a tertiary care academic medical center and compared labor induction outcomes with vaginal misoprostol to outcomes with oral misoprostol after a complete institutional shift to oral misoprostol. Labor induction using 25 micrograms vaginal misoprostol in 2013-2014 was compared with 50 micrograms oral misoprostol in 2014-2015. The primary outcome was cesarean delivery. Secondary outcomes included time to vaginal delivery, uterine tachysystole, maternal hemorrhage, and composite adverse neonatal outcomes. Demographics and outcomes were analyzed using standard statistical tests. Multivariable regression models accounting for potential confounders were created for the primary and secondary outcomes with adjusted odds ratios (aOR) as the measures of effect.

RESULTS

There were 138 women in the oral and 138 women in the vaginal misoprostol groups. In the overall cohort, the median (interquartile range) body mass index was 31.7 (28.2-36.8) and most women (72%) were of either black or Hispanic race or ethnicity. The frequency of cesarean delivery was higher in the oral than the vaginal misoprostol group (32% vs 21%; P=.04). The adjusted odds of cesarean was higher with oral misoprostol (aOR 2.01; 95% CI 1.07-3.76). Among nulliparous women, the frequency of cesarean delivery was 41% in the oral and 28% in the vaginal misoprostol groups (aOR 2.79; 95% CI 1.26-6.19). Women had a longer time to vaginal delivery in the oral compared with vaginal misoprostol group (41 vs 31 hours respectively, P=.01). Tachysystole occurred more frequently with vaginal misoprostol (20% vs 11%; P=.04).

CONCLUSION

Compared with vaginal misoprostol, oral misoprostol may be associated with increased risk of cesarean delivery and longer time to vaginal delivery.

Induction of labour in nulliparous women- quick or slow: a cohort study comparing slow-release vaginal insert with low-dose misoprostol oral tablets

Background

This study was undertaken with the objective of comparing efficacy and safety for two different regimens using misoprostol for induction of labour.

Methods

The study was set in two different hospitals in the region of Zeeland, Denmark, and designed as a prospective cohort study. Nulliparous women with unripe cervix, eligible for vaginal delivery and medical induction of labour were included. Exclusion criteria were a previous uterine scar, suspicion of growth restriction of the fetus and prelabour rupture of membranes.

One department used 25 mcg oral misoprostol tablets and the other department used 200 mcg slow-release misoprostol vaginal insert, for induction of labour.

Primary outcomes were predefined as frequency of cesarean section, tachysystole and delivery within 24 h. Secondary outcomes were: time from induction to delivery, use of additional methods for induction, postpartum hemorrhage, anal sphincter rupture, epidural, pyrexia (rectal temperature >  38.5 °C), prolonged rupture of membranes, and use of tocolysis.

Results

No significant differences in women achieving vaginal delivery was found. However, a significantly increased risk of tachysystole for the vaginal administration route was observed; 28.4% compared with 2.3%. There were no events of serious neonatal asphyxia. Half of the women induced with vaginal insert delivered within 24 h, compared with 16.8% of the women induced with oral misoprostol.

Conclusions

Induction with vaginal slow-release misoprostol leads to quicker delivery with an increased risk of tachysystole but with similar perinatal outcomes and rates of cesarean sections. Low-dose oral misoprostol appears to be safe, however it leads to an increased use of secondary methods and a tendency of more intrapartum pyrexia.

Trial registration

Clinicaltrials.gov ID: NCT02693587 on February 262,016.

EudraCT number 2020–000366-42 on 23 January 2020, retrospectively registered.

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.

A comparison of misoprostol vaginal insert and misoprostol vaginal tablets for induction of labor in nulliparous women: a retrospective cohort study

Background

Since Misoprostol Vaginal Insert (MVI - Misodel ®) was approved for labor induction in Europe in 2013, to date, no study has been published comparing MVI to Misoprostol vaginal tablets (MVT). The aim of this study, performed as part of a quality improvement project, was to compare the efficacy and safety of 200 μg MVI versus 25 μg MVT for labor induction in nulliparous women.

Methods

This retrospective cohort study included 171 nulliparous singleton term deliveries induced with MVI (n = 85) versus MVT (n = 86) at Oslo University Hospital Rikshospitalet, Norway, from November 2014 to December 2015. Primary outcomes were time from drug administration to delivery in hours and minutes and the rate of cesarean section (CS). Results were adjusted for Bishop Score and pre-induction with balloon catheter.

Results

Median time from drug administration to delivery was shorter in the MVI group compared to the MVT group (15 h 43 min versus 19 h 37 min, p = 0.011). Adjusted for confounding factors, mean difference was 6 h 3 min (p = 0.002). The risk of CS was 67% lower in the MVI group compared to the MVT group (11.8% versus 23.3%, OR = 0.33; adjusted 95% CI 0.13–0.81). Adverse neonatal outcomes did not differ between the groups.

Conclusions

In a setting of routine obstetric care, MVI seems to be a more efficient labor induction agent than MVT, and with a lower CS rate and no increase in adverse infant outcomes.

Oral Misoprostol Solution for Induction of Labour

OBJECTIVE

To determine the effects of oral misoprostol solution for induction of labour.

STUDY DESIGN

This is a prospective observational study.

SETTING

This study was conducted in Government Medical College, Aurangabad.

METHOD

Patients undergoing induction of labour after 36 weeks of pregnancy were allocated by randomization to induction of labour with oral misoprostol solution administered 2 h apart. Delivery within 24 h after induction with oral misoprostol solution was the primary outcome on which the sample size was based. The data were analysed by Statistical Software for Social Sciences software.

RESULT

Two hundred patients were randomly selected for induction with oral misoprostol solution. There were no significant differences in substantive outcomes. Vaginal delivery within 24 h was achieved in 80.5 % of patients. The caesarean section rate was 19.5 %. Uterine hyperactivity occurred in 4 % of patients. The response to induction of labour in women with unfavourable cervices (modified Bishop's score <2) was somewhat slower with misoprostol, induction to delivery interval was more, oxytocin requirement was more, and vaginal delivery rate was less.

CONCLUSION

This new approach to oral misoprostol solution administration was successful in achieving vaginal delivery rate in 24 h in 80.5 % of patients; rate of LSCS was less 19.5 %.

Outcome of misoprostol and oxytocin in induction of labour

BACKGROUND

Induction of labour is the process of initiating the labour by artificial means from 24 weeks of gestation. The main aim of this study is to find out the maternal and foetal outcomes after induction of labour with misoprostol and oxytocin beyond 37 weeks of gestation.

METHODS

This was a hospital-based observational study carried out at Paropakar Maternity and Women's Hospital, Nepal. Misoprostol of 25 µg was inserted in posterior fornix of vagina or oxytocin infusion was started from 2.5 units on whom induction was decided. Maternal and foetal/neonatal outcomes were observed. Collected data were analysed using SPSS and MS Excel.

RESULTS

General induction rate was found to be 7.2%. In this study, post-term pregnancy was found to be the most common reason for induction of labour. Analysis of onset of labour led to the finding that mean onset of labour was much rapid in oxytocin (6.6 h) than misoprostol (13.6 h). However, there is similarity in induction-delivery interval in both groups. Overall, the rate of normal delivery and caesarean section was found to be 64.9% and 33.2%, respectively. Similarly, normal delivery within 12 h was seen in 18.4% of the patients given with misoprostol and 43.5% in oxytocin group. Foetal distress was found as the most common reason for caesarean section. The overall occurrence of maternal complication was found to be similar in misoprostol and oxytocin groups, nausea/vomiting being the most common (36.7%) complication followed by fever (24.1%). Besides this, the most common neonatal complication found in overall cases was meconium stained liquor (49.2%).

CONCLUSION

It was found that misoprostol was used most frequently for induction of labour compared to oxytocin. The onset of labour was found to be rapid in oxytocin than misoprostol. However, the occurrence of side effects was found to be similar in both misoprostol and oxytocin groups.

An elevated amniotic fluid prostaglandin F2α concentration is associated with intra-amniotic inflammation/infection, and clinical and histologic chorioamnionitis, as well as impending preterm delivery in patients with preterm labor and intact membranes

OBJECTIVE

To determine whether an elevated amniotic fluid concentration of prostaglandin F2α (PGF2α) is associated with intra-amniotic inflammation/infection and adverse pregnancy outcomes in patients with preterm labor and intact membranes.

MATERIALS AND METHODS

The retrospective cohort study included 132 patients who had singleton pregnancies with preterm labor (< 35 weeks of gestation) and intact membranes. Amniotic fluid was cultured for aerobic and anaerobic bacteria as well as for genital mycoplasmas. Intra-amniotic inflammation was defined by an elevated amniotic fluid matrix metalloproteinase-8 (MMP-8) concentration (>23 ng/mL). PGF2α was measured with a sensitive and specific immunoassay. The amniotic fluid PGF2α concentration was considered elevated when it was above the 95th percentile among pregnant women at 15-36 weeks of gestation who were not in labor (≥170 pg/mL).

RESULTS

(1) The prevalence of an elevated amniotic fluid PGF2α concentration was 40.2% (53/132) in patients with preterm labor and intact membranes; (2) patients with an elevated amniotic fluid PGF2α concentration had a significantly higher rate of positive amniotic fluid culture [19% (10/53) versus 5% (4/79); p = 0.019], intra-amniotic inflammation/infection [49% (26/53) versus 20% (16/79); p = 0.001], spontaneous preterm delivery, clinical and histologic chorioamnionitis, and funisitis, as well as a higher median amniotic fluid MMP-8 concentration and amniotic fluid white blood cell count and a shorter amniocentesis-to-delivery interval than those without an elevated concentration of amniotic fluid PGF2α (p < 0.05 for each); and (3) an elevated amniotic fluid PGF2α concentration was associated with a shorter amniocentesis-to-delivery interval after adjustment for the presence of intra-amniotic inflammation/infection [hazard ratio 2.1, 95% confidence interval (CI) 1.4-3.1; p = 0.001].

CONCLUSION

The concentration of PGF2α was elevated in the amniotic fluid of 40.2% of patients with preterm labor and intact membranes and is an independent risk factor for intra-amniotic inflammation/infection, impending preterm delivery, chorioamnionitis, and funisitis.

Umbilical cord prostaglandins in term and preterm parturition

OBJECTIVE

Prostaglandins (PGs) are considered the universal mediators of parturition. Amniotic fluid PGE2 and PGF2α concentrations increase before the onset of spontaneous labor at term, as well as during labor. This study was conducted to determine if the concentrations of umbilical cord PGE2 and PGF2α change with advancing gestational age, spontaneous labor at term, and preterm labor (with and without funisitis).

METHODS

Umbilical cord (UC) tissue samples were obtained from women (N = 158) with singleton pregnancies in the following groups: (1) term deliveries without labor (TNL; n = 20); (2) term deliveries with labor (TIL; n = 20); (3) spontaneous preterm deliveries (sPTD) with (n = 20) and without acute funisitis (n = 20); and (4) preeclampsia without labor (n = 78). The concentrations of PGs were determined in different locations of the UC. PGE2 and PGF2α were measured by specific immunoassays. Non-parametric statistics were used for analysis.

RESULTS

(1) In spontaneous preterm deliveries, the median UC PGE2 concentration was higher in cases with funisitis than in those without funisitis (233.7 pg/µg versus 87.4 pg/µg of total protein, p = 0.001); (2) the median UC PGE2 concentration in sPTD with funisitis was also higher than that obtained from samples who had undergone labor at term (233.7 pg/µg versus 116.1 pg/µg of total protein, p = 0.03); (3) the UC PGE2 and PGF2α concentration increased as a function of advancing gestational age before 36 weeks (PGE2: ρ = 0.59, p < 0.001; PGF2α: ρ = 0.39, p = 0.01), but not after 36 weeks (PGE2: ρ = -0.1, p = 0.5; PGF2α: ρ = -0.2, p = 0.2); (4) the median UC concentrations of PGE2 and PGF2α at term was similar in samples obtained from women with and without labor (PGE2: TNL 133.7 pg/µg versus TIL 116.1 pg/µg of total protein, p = 0.9; PGF2α: TNL 8.4 pg/µg versus TIL 8.1 pg/µg of total protein, p = 0.7); and (5) there was no correlation between UC PG concentration and gestational age at term pregnancy (PGE2: ρ = 0.01, p = 0.9; PGF2α: ρ = 0.07, p = 0.7).

CONCLUSIONS

(1) PGE2 concentrations in the UC are higher in the presence of acute funisitis than in the absence of this lesion; (2) spontaneous labor at term was not associated with a change in the UC concentration of PGE2 and PGF2α; and (3) the UC concentrations of PGE2 and PGF2α increased as a function of gestational age. We propose that UC PGs act as inflammatory mediators generated in the context of fetal systemic inflammation.

Oral misoprostol for induction of labour

BACKGROUND

Misoprostol is an orally active prostaglandin. In most countries misoprostol is not licensed for labour induction, but its use is common because it is cheap and heat stable.

OBJECTIVES

To assess the use of oral misoprostol for labour induction in women with a viable fetus.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (17 January 2014).

SELECTION CRITERIA

Randomised trials comparing oral misoprostol versus placebo or other methods, given to women with a viable fetus for labour induction.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial data, using centrally-designed data sheets.

MAIN RESULTS

Overall there were 76 trials (14,412) women) which were of mixed quality.In nine trials comparing oral misoprostol with placebo (1109 women), women using oral misoprostol were more likely to give birth vaginally within 24 hours (risk ratio (RR) 0.16, 95% confidence interval (CI) 0.05 to 0.49; one trial; 96 women), need less oxytocin (RR 0.42, 95% CI 0.37 to 0.49; seven trials; 933 women) and have a lower caesarean section rate (RR 0.72, 95% CI 0.54 to 0.95; eight trials; 1029 women).In 12 trials comparing oral misoprostol with vaginal dinoprostone (3859 women), women given oral misoprostol were less likely to need a caesarean section (RR 0.88, 95% CI 0.78 to 0.99; 11 trials; 3592 women). There was some evidence that they had slower inductions, but there were no other statistically significant differences.Nine trials (1282 women) compared oral misoprostol with intravenous oxytocin. The caesarean section rate was significantly lower in women who received oral misoprostol (RR 0.77, 95% CI 0.60 to 0.98; nine trials; 1282 women), but they had increased rates of meconium-stained liquor (RR 1.65, 95% CI 1.04 to 2.60; seven trials; 1172 women).Thirty-seven trials (6417 women) compared oral and vaginal misoprostol and found no statistically significant difference in the primary outcomes of serious neonatal morbidity/death or serious maternal morbidity or death. The results for vaginal birth not achieved in 24 hours, uterine hyperstimulation with fetal heart rate (FHR) changes, and caesarean section were highly heterogenous - for uterine hyperstimulation with FHR changes this was related to dosage with lower rates in those with lower doses of oral misoprostol. However, there were fewer babies born with a low Apgar score in the oral group (RR 0.60, 95% CI 0.44 to 0.82; 19 trials; 4009 babies) and a decrease in postpartum haemorrhage (RR 0.57, 95% CI 0.34 to 0.95; 10 trials; 1478 women). However, the oral misoprostol group had an increase in meconium-stained liquor (RR 1.22, 95% CI 1.03 to 1.44; 24 trials; 3634 women).

AUTHORS' CONCLUSIONS

Oral misoprostol as an induction agent is effective at achieving vaginal birth. It is more effective than placebo, as effective as vaginal misoprostol and results in fewer caesarean sections than vaginal dinoprostone or oxytocin.Where misoprostol remains unlicensed for the induction of labour, many practitioners will prefer to use a licensed product like dinoprostone. If using oral misoprostol, the evidence suggests that the dose should be 20 to 25 mcg in solution. Given that safety is the primary concern, the evidence supports the use of oral regimens over vaginal regimens. This is especially important in situations where the risk of ascending infection is high and the lack of staff means that women cannot be intensely monitored.

Comparative evaluation of 50 microgram oral misoprostol and 25 microgram intravaginal misoprostol for induction of labour at term: a randomized trial

OBJECTIVES

To assess and compare the efficacy and safety of 50 µg oral misoprostol and 25 µg intravaginal misoprostol for induction of labour at term.

METHODS

This non-blinded, randomized clinical trial included 228 pregnant women at term with obstetric or medical indications for induction of labour. Women either took 50 µg misoprostol orally (two 25 µg tablets) or had one 25 µg tablet of misoprostol inserted in the posterior vaginal fornix. In each group, misoprostol administration was repeated every four hours in the same dose until regular uterine contractions were established or to a maximum of five doses. Time to delivery and outcome data for each group were compared.

RESULTS

Of the 228 women, eight (3.5%) were excluded from the analysis as they withdrew their consent after randomization. Mean induction-to-delivery interval was similar in both groups (21.22 hours in the oral group vs. 20.15 hours in the vaginal group; P = 0.58). There was no significant difference between the groups with respect to the number of women who delivered within 24 hours or who required oxytocin augmentation of labour, the mode of delivery, and neonatal outcomes (P > 0.05). Uterine hyperstimulation occurred in two women who received misoprostol vaginally, but not in any of the women in the oral misoprostol group.

CONCLUSION

Oral misoprostol in a dose of 50 µg every four hours, to a maximum of five doses, has the potential to induce labour as safely and effectively as 25 µg misoprostol administered vaginally every four hours.

Comparative study of efficacy and safety of oral versus vaginal misoprostol for induction or labour

OBJECTIVE

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

DESIGN

A randomized trial.

SETTING

Tertiary care hospital.

PARTICIPANTS

Two hundred women requiring induction of labour.

METHODS

Group A received oral misoprostol 50 mcg 6 hourly maximum 4 doses to 100 patients and Group B received vaginal misoprostol 50 mcg 6 hourly maximum 4 doses to 100 patients. When the patient entered active stage of labour i.e. clinically adequate constractions of 3/10 min of >40 s duration, and cervical dilatation of with 4 cm, further doses of misoprostol were not administered. Statistical analysis was done using chi-square test and t test.

RESULT

Both groups were comparable with respect to maternal age, gestational age, indication of induction and initial modified Bishops score Mean number of dosage required for successful induction were significantly less in vaginal group than oral group (in oral groups A were 2.73 + 0.58, and in vaginal Group B 2.26 + 0.52, P value < 0.0001 highly significant). The induction delivery interval was significantly less in vaginal group than oral group (Group A 15.24 + 3.47 h Group B 12.74 + 2.60 h, P < 0.0001 highly significant). Oxytocin augmentation required was less in vaginal group. 26 caesarean sections were performed in oral group and 17 caesarean sections were done in vaginal group (P value 0.06 NS). APGAR score, birth weight, NICU admissions showed no difference between the two groups.

CONCLUSION

This study shows that vaginal route of administration of misoprostol is preferable to oral route for induction of labour when used in equivalent dosage of 50 mcg 6 hourly.

Early amniotomy after vaginal misoprostol for induction of labor: a randomized clinical trial

OBJECTIVES

To test the effectiveness and safety of early amniotomy after vaginal misoprostol for the induction of labor.

STUDY DESIGN

A randomized clinical trial that included 320 women with medical or obstetric indication for labor induction. They were randomly assigned into two equal groups, amniotomy group and control group. Each participant received vaginal misoprostol 50 μg every 6 h for induction of labor. In amniotomy group, amniotomy was done in the early active phase of labor while in the control group, the membranes were left to rupture spontaneously or as judged by the senior resident in the duty.

RESULTS

More subjects in the amniotomy group achieved vaginal delivery within 24 h than in the control group [117 (73.13 %) vs. 105 (65.63 %)]. Subjects in the amniotomy group reported shorter induction to delivery interval (09.72 ± 4.61 h vs. 13.61 ± 5.61, P = .002), and better neonatal outcome compared to the control group. There were no statistically significant differences between both group with regard to number of doses of misoprostol, need for oxytocin, Cesarean Section indication and maternal side effects.

CONCLUSION

Early amniotomy after vaginal misoprostol for labor induction is associated with higher successful vaginal delivery rate, shorter labor duration and better neonatal outcome.

Prediction of successful labor induction using transvaginal sonographic cervical measurements

PURPOSE

To predict the success of labor induction by sonographic cervical measurements, maternal/obstetrical factors, and the Bishop's score.

METHODS

Between February 2008 and February 2010, 190 consecutive pregnant women underwent clinical examination to assess the Bishop's score and transvaginal sonographic cervical measurements (cervical length, fetal head stage, and cervical dilatation) before labor induction. The following outcomes were analyzed: overall vaginal delivery and vaginal delivery up to 24 hours after labor induction.

RESULTS

Overall vaginal delivery occurred in 133 (70.0%) patients and vaginal delivery 24 hours after labor induction happened in 119 (62.6%) patients. The sonographic cervical measurements were significantly associated with all outcomes (p < 0.01). The areas under the ROC curve (AUC) of all ultrasound cervical parameters to predict the two events were 68.9% and 72.0% (cervical length); 71.6% and 73.6% (fetal head stage); and 72.0% and 73.4% (cervical dilatation). Mathematical equations were obtained to calculate the probability for each event considering the sonographic cervical measurements in association with clinical factors after regression analysis, which increased the AUC for both events (80.1% and 79.3%).

CONCLUSIONS

Transvaginal sonographic cervical measurements can predict the successful labor induction, especially when associated to clinical analysis (Bishop's score).

A prospective double blind study using oral versus vaginal misoprostol for labour induction

This prospective double blind study was undertaken to compare the safety and efficacy of oral vs vaginal misoprostol in equivalent doses (50 microg) for induction of labour. A total of 128 term pregnancies with indication for induction of labour were allocated to two groups to receive 50 microg misoprostol orally or vaginally, every 4 h until adequate contractions were achieved or a maximum of 200 microg dose. Induction to delivery interval was significantly shorter in the vaginal group compared with the oral group (14.6 h vs 22.5 h; p < 0.001). There was no significant difference between the groups with respect to mode of delivery, neonatal outcome and maternal side-effects. However, the incidence of abnormal contractility pattern was more common in the vaginal group (10/68, 14.6%) as compared with the oral group (4/60, 6.6%) (p = 0.146).

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.

Comparison of labor induction with titrated oral misoprostol solution between nulliparous and multiparous women

AIM

To compare the outcomes of labor induction with oral misoprostol solution between nulliparous and multiparous women.

METHODS

We retrospectively reviewed the medical records of all patients between 37 and 42 weeks of gestation with a Bishop score <or=6 who underwent labor induction with titrated oral misoprostol solution. The women were allocated into two groups: nulliparous and multiparous. The women received one basal unit of misoprostol solution (20 mL, 1 microg/mL) every hour for four doses; additional doses were titrated against individual uterine response. The interval of latent and active phase and vaginal delivery within 12 h were the primary outcomes.

RESULTS

Of the 112 women included in the study, 49 (43.8%) mulliparae and 63 (56.2%) multiparae underwent labor induction with titrated oral misoprostol solution. Complete vaginal delivery occurred within 12 h in 21 (42.9%) nulliparae and 54 (85.7%) multiparae (RR, 0.54; 95% CI, 0.39-0.76). All induction intervals, including the latent and active phases, were significantly shorter in the multiparous group (P < 0.01). Induction failure did not occur in any patient in either of the groups. There were no instances of hyperstimulation, which was defined as tachysystole or hypertonus with nonreassuring fetal heart rate pattern, although tachysystole, defined as the presence of at least six contractions in 10 min over at least two 10-min windows, occurred in four (8.2%) nulliparous women and in four (6.3%) multiparous women. Hypertonus, defined as a single contraction lasting more than 2 min, did not occur in either group. None of the neonates in either group had an Apgar score of <7 at 1 min.

CONCLUSION

Titrated oral misoprostol solution is a promising method of labor induction for both nulliparous and multiparous women.

Titrated oral compared with vaginal misoprostol for labor induction: a randomized controlled trial

OBJECTIVE

To compare the efficacy and safety of titrated oral misoprostol and vaginal misoprostol for labor induction.

METHODS

Women between 34 and 42 weeks of gestation with an unfavorable cervix (Bishop score less than or equal to 6) and an indication for labor induction were randomLy assigned to receive titrated oral or vaginal misoprostol. The titrated oral misoprostol group received a basal unit of 20 mL misoprostol solution (1 mcg/mL) every 1 hour for four doses and then were titrated against individual uterine response. The vaginal group received 25 mcg every 4 hours until attaining a more favorable cervix. Vaginal delivery within 12 hours was the primary outcome. The data were analyzed by intention-to-treat.

RESULTS

Titrated oral misoprostol was given to 101 (48.8%) women and vaginal misoprostol to 106 (51.2%) women. Completed vaginal delivery occurred within 12 hours in 75 (74.3%) women in the titrated oral group and 27 (25.5%) women in the vaginal group (relative risk [RR] 8.44, 95% confidence interval [CI] 4.52-15.76). The incidence of hyperstimulation was 0.0% in the titrated oral group compared with 11.3% in the vaginal group (RR 0.08, 95% CI 0.01-0.61). Although more women experienced nausea (10.9%) in the titrated oral group (RR 27.07, 95% CI 1.57-465.70), fewer infants had Apgar scores of less than 7 at 1 minute in the titrated oral group than in the vaginal group (RR 0.10, 95% CI 0.01-0.76).

CONCLUSION

Titrated oral misoprostol is associated with a lower incidence of uterine hyperstimulation and a lower cesarean delivery rate than vaginal misoprostol for labor induction in patients with unfavorable cervix.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, www.clinicaltrials.gov, NCT00529295

LEVEL OF EVIDENCE

I.

Pilot study of labor induction with titrated oral misoprostol

OBJECTIVE

To evaluate the safety and efficacy of titrated oral misoprostol for labor induction at term.

MATERIALS AND METHODS

Seventy-seven pregnant women (37 nullipara and 40 multipara), with medical or obstetric indications for labor induction after 37 weeks of gestation and unfavorable cervices (Bishop's score < 7), were induced according to the principles of titrated oral doses of misoprostol against uterine response. Our primary outcome measurements were the percentage of patients who had a vaginal delivery within 24 hours of induction and the interval from induction to vaginal delivery. Secondary measurements included oxytocin requirement, total misoprostol dosage, number of cesarean deliveries, induction failure, uterine hyperstimulation rates and neonatal outcomes.

RESULTS

Seventy-five women (97.4%) experienced active labor within 24 hours, with 72 (93.5%) completing vaginal delivery within 24 hours. The mean interval from induction to vaginal delivery for all the women was 9.7 hours, with a 2.3-hour active phase. The mean misoprostol dosage was 206 microg, with eight women (10.4%) requiring oxytocin augmentation. There was no uterine hyperstimulation or induction failure, except for seven cases of uterine tachysystole (9.1%).

CONCLUSION

Titrated oral misoprostol is a safe and effective method of labor induction because the dosage can be adjusted according to individual response.

Oral Misoprostol Administration for Labor Induction

Using oral agents for induction of labor would reduce the need for repeated vaginal examinations; this is more acceptable to women and could reduce infection rates. A systematic review was conducted of 41 randomized trials comparing oral misoprostol to other induction agents. Oral misoprostol is effective at achieving vaginal delivery, and may have benefits over both vaginal and intracervical dinoprostone. Although it does not achieve vaginal delivery as quickly as vaginal misoprostol, the rates of hyperstimulation are lower when using comparable doses. As the primary consideration should be safety rather than speed, an oral regimen using a maximum of 50 mcg 4 hourly is recommended.

The routine use of oxytocin after oral misoprostol for labour induction in women with an unfavourable cervix is not of benefit

BACKGROUND

Induction of labour with misoprostol is often augmented with oxytocin with the possible consequence of uterine hypercontractility. It is important to determine whether the use of oxytocin in this circumstance has benefit as well as risk.

AIM

To compare two regimens for labour induction in women with an unfavourable cervix: oral misoprostol vs. oral misoprostol routinely followed by oxytocin.

METHODS

A prospective randomised trial in which 200 women with an unfavourable cervix received either oral misoprostol 25 microg every 3 h (group 1, n = 100) or two such doses routinely followed by oxytocin (group 2, n = 100). Outcomes included change in Bishop score, induction delivery interval, oxytocin requirement, contraction abnormalities, mode of delivery and neonatal outcome.

RESULT

The improvement in Bishop score with two misoprostol doses in all 200 women was highly significant (2.9 +/- 1.5 to 6.6 +/- 1.9, P < 0.0001). The induction delivery interval, Caesarean delivery rate, vaginal delivery rate within 24 h, contraction abnormalities and neonatal outcome were similar in both groups. Contraction abnormalities were remarkably low with either regimen (1%). Routine addition of oxytocin 3 h after the second misoprostol dose (group 2) resulted in the maximum oxytocin dose (64 mU/min) being given to more women (66% in group 2; 36% in group 1).

CONCLUSION

There was no benefit of routine addition of oxytocin after two doses of misoprostol. Reduced oxytocin requirement was observed when it was added only if needed. Both regimens achieved 85-87% vaginal deliveries with low incidence of hypercontractility.

Oral misoprostol for induction of labour

BACKGROUND

Misoprostol is a synthetic prostaglandin that can be given orally or vaginally. In most countries misoprostol has not been licensed for use in pregnancy, but its unlicensed use is common because misoprostol is cheap, stable at room temperature and effective in causing uterine contractions. Oral use of misoprostol may be convenient, but high doses could cause uterine hyperstimulation and uterine rupture which may be life-threatening for both mother and fetus.

OBJECTIVES

To assess the effectiveness and safety of oral misoprostol used for labour induction in women with a viable fetus in the third trimester of pregnancy.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group Trials Register (January 2005).

SELECTION CRITERIA

Randomised trials comparing oral misoprostol versus other methods, placebo or no treatment, given to women with a viable fetus for labour induction.

DATA COLLECTION AND ANALYSIS

Three authors independently assessed trial quality and extracted data, using centrally-designed data sheets.

MAIN RESULTS

Forty-one trials (8606 participants) were included. In four trials comparing oral misoprostol with placebo (474 participants), women using oral misoprostol were less likely to have long labours (relative risk (RR) 0.16, 95% confidence interval (CI) 0.05 to 0.49), needed less oxytocin (RR 0.32, 95% CI 0.24 to 0.43) and had a lower caesarean section rate (RR 0.62, 95% CI 0.40 to 0.96). In nine trials comparing oral misoprostol with vaginal dinoprostone (2627 participants), women given oral misoprostol were less likely to need a caesarean section, but this reduction reached statistical significance only in the subgroup with intact membranes (RR 0.78, 95% CI 0.66 to 0.94). Uterine hyperstimulation was more common after oral misoprostol (RR 1.63, 95% CI 1.09 to 2.44) although this was not associated with any adverse fetal events. Seven trials (1017 participants) compared oral misoprostol with intravenous oxytocin. The only difference between the groups was an increase in meconium-stained liquor in women with ruptured membranes following administration of oral misoprostol (RR 1.72, 95% 1.08 to 2.74). Sixteen trials (3645 participants) compared oral and vaginal misoprostol and found no difference in the primary outcomes. There was less uterine hyperstimulation without fetal heart rate changes in those given oral misoprostol (RR 0.37, 95% 0.23 to 0.59). Oral misoprsotol was associated with increased need for oxytocin augmentation (RR 1.28, 95% 1.11 to 1.48) and more meconium-stained liquor (RR 1.27, 1.01 to 1.60).

AUTHORS' CONCLUSIONS

Oral misoprostol appears to be more effective than placebo and at least as effective as vaginal dinoprostone. However, there remain questions about its safety because of a relatively high rate of uterine hyperstimulation and the lack of appropriate dose ranging studies. In countries where misoprostol remains unlicenced for the induction of labour, many practitioners will prefer the legal protection of using a licenced product like dinoprostone. There is no evidence that misoprostol given orally is inferior to the vaginal route and has lower rates of hyperstimulation. If misoprostol is used orally, the dose should not exceed 50 mcg.

A comparison of oral and vaginal misoprostol for induction of labor

OBJECTIVE

The aim of the study is to compare the efficacy and safety of oral (100 microg) and vaginal (50 microg) misoprostol for labor induction.

STUDY DESIGN

Ninety-nine patients with indications for labor induction randomly received 100 microg oral misoprostol every 4 h or 50 microg vaginal misoprostol every 4 h, using maximum six doses. Mean induction to delivery interval, mode of delivery, rates of tachysystole, hypertonus and hyperstimulation syndrome, oxytocin use, number of doses used, failed induction rate and neonatal outcomes were compared for the two groups.

RESULTS

Mean dose of misoprostol used for oral and vaginal misoprostol groups were 2.17+/-1.35 and 1.91+/-0.94, respectively (p=0.65). There were two failed inductions in the oral (4%) and one failed induction (2.5%) in the vaginal group after a total of six doses of misoprostol (p=0.58). There was no significant difference for the mean induction to delivery interval, to the beginning of active phase interval, active phase duration, second stage duration and the number of women who received oxytocin for induction or augmentation between the two groups (p>0.05). There were also no significant differences for intrapartum complications and neonatal outcomes between the oral and vaginal misoprostol groups (p>0.05).

CONCLUSION

Our findings indicate that, in a closely supervised hospital setting with adequate monitoring, 100 microg oral misoprostol has the potential to induce labor as safely and effectively as its 50 microg vaginal analogue. As oral use of the drug is easier for both the patient and the doctor, oral misoprostol will probably be more preferable than the vaginal route.

Oral, vaginal and sublingual misoprostol for induction of labor

OBJECTIVE

To evaluate the effectiveness and safety of different administration routes of misoprostol for induction of labor.

METHOD

PubMed, Cochrane Library and EMBASE searches were carried out using the keywords oral, vaginal, sublingual, buccal, misoprostol, labor induction, identifying randomized case-controlled trials comparing different routes for giving misoprostol to induce labor, published in English between 1994 and 2004.

RESULTS

Seventeen studies (3549 participants) were included. Compared to vaginal administration, oral misoprostol was associated with higher failure rates for achieving vaginal delivery within 24 h (odds ratio (OR) 1.61, 95% confidence interval (CI) 1.23-2.10), higher rates of uterine hyperstimulation without fetal heart rate (FHR) changes (OR 2.21, 95% CI 1.12-4.34) and lower cesarean section rates (OR 0.74, 95% CI 0.56-0.97). A lower dose of oral misoprostol (50 microg) compared to the 25-50 microg administered vaginally was associated with a higher rate of vaginal delivery not being achieved within 24 h (OR 3.60, 95% CI 2.10-6.18), more need for oxytocin augmentation (OR 2.19, 95% CI 1.65-2.92), less uterine hyperstimulation both without FHR changes (OR 0.58, 95% CI 0.42-0.80) and with FHR changes (OR 0.34, 95% CI 0.17-0.67) and fewer cesarean sections (OR 0.69, 95% CI 0.51-0.91). Compared to vaginal administration, buccal misoprostol resulted in a higher rate of failure to achieve vaginal delivery after 24 h, more frequent uterine hyperstimulation and lower rates of cesarean section, but these differences were not significant. When 50 mug of misoprostol used sublingually was compared to oral administration, the sublingual misoprostol was associated with less failure to achieve vaginal delivery after 24 h, less oxytocin augmentation and reduced cesarean section, but none of the differences were statistically significant.

CONCLUSIONS

Vaginal misoprostol appears more effective than the equivalent dosage administered orally. However, the vaginal route appears to be associated with a higher risk of uterine hyperstimulation. Sublingual misoprostol seems an effective route of administration, but a lack of data necessitates more clinical trials to establish the effectiveness and safety of the buccal/sublingual route.

Induction of labor

The rate of labor induction continues to rise significantly in the United States because of a growing use of labor induction for postterm pregnancies and elective induction of labor. Although different types and doses of prostaglandins used for cervical ripening often initiate uterine activity, the principal role of these agents is to soften the unripe cervix independent of uterine activity. Several systematic reviews with meta-analyses have shown that prostaglandins are superior to placebo and oxytocin alone in ripening of the cervix. Numerous studies and meta-analyses have assessed misoprostol's efficacy and safety as a labor induction agent. The most appropriate dose and route of administration has not yet been confirmed.

Prospective randomized clinical trial of inpatient cervical ripening with stepwise oral misoprostol vs vaginal misoprostol

OBJECTIVE

The purpose of this study was to compare the efficacy and safety of stepwise oral misoprostol vs vaginal misoprostol for cervical ripening before induction of labor.

STUDY DESIGN

Two hundred and four women between 32 to 42 weeks of gestation with an unfavorable cervix (Bishop score < or = 6) and an indication for labor induction were randomized to receive oral or vaginal misoprostol every 4 hours up to 4 doses. The oral misoprostol group received 50 microg initially followed by 100 microg in each subsequent dose. The vaginal group received 25 microg in each dose. The primary outcome was the interval from first misoprostol dose to delivery. Patient satisfaction and side effects were assessed by surveys completed after delivery.

RESULTS

Ninety-three (45.6%) women received oral misoprostol; 111 (54.4%) received vaginal misoprostol. There was no difference in the average interval from the first dose of misoprostol to delivery in the oral (21.1 + 7.9 hrs) and vaginal (21.5 + 11.0 hrs, P = NS) misoprostol groups. The incidence of hyperstimulation in the oral group was 2.2% vs 5.4% in the vaginal group, P = NS. Eighteen patients in the oral group (19.4%) and 36 (32.4%) in the vaginal group underwent cesarean section (P < .05). This difference was attributed to better tolerance of more doses of misoprostol by the women in the oral group. There was no difference in side effects (nausea, vomiting, diarrhea, shivering) between groups. Fourteen percent of women in the vaginal group versus 7.5% in the oral group were dissatisfied with the use of misoprostol (P = NS).

CONCLUSION

Stepwise oral misoprostol (50 microg followed by 100 microg) appears to be as effective as vaginal misoprostol (25 microg) for cervical ripening with a low incidence of hyperstimulation, no increase in side effects, a high rate of patient satisfaction, and is associated with a lower cesarean section rate.

Oral misoprostol versus intracervical dinoprostone for induction of labor

OBJECTIVES

To compare oral misoprostol with dinoprostone for induction of labor and their effects on the fetal heart rate patterns.

METHODS

In a randomized controlled trial, 200 patients received either misoprostol 50 mug orally for every 4 h, or dinoprostone 0.5 mg intracervically for every 6 h. Cardiotocographic recordings, in 10-min windows 30, 60, and 80 min after prostaglandin administration during induction and continuously during labor, were compared between the two groups. Primary outcome for effectiveness and safety was assessed in terms of the number of vaginal deliveries within 24 h and fetal heart rate abnormalities during induction and labor respectively.

RESULTS

Data from 96 patients in the misoprostol group and 95 in the dinoprostone group were analyzed. There were no significant differences in respect of the number of vaginal deliveries within 24 h (RR 1.12; 95% CI 0.88-1.42). The frequency of suspicious and pathological fetal heart rate patterns did not differ significantly but significantly more cardiotocographs in the dinoprostone group had non-reassuring baseline variability 60 min after dose administration (RR 0.33; 95% CI 0.14-0.77). Maternal and neonatal outcomes did not differ significantly.

CONCLUSION

Oral misoprostol is as effective as intracervical dinoprostone for induction of labor with no difference in the frequency of fetal heart rate abnormalities.

Management of late intrauterine death using a combination of mifepristone and misoprostol—experience of two regimens

OBJECTIVE

To determine the safety and effectiveness of managing intrauterine death after 24 weeks gestation using a combination of mifepristone and misoprostol.

STUDY DESIGN

Two regimens are compared. Twenty-nine women (group one) were managed using a combination of oral mifepristone and vaginal/oral misoprostol. After a change in dosage and route of administration, a further 20 women were managed with oral mifepristone and vaginal misoprostol (group two).

RESULTS

All women delivered vaginally. The mean induction to delivery interval in group one was 7 h compared with 10.2 h in group two. Group two experienced fewer gastrointestinal side-effects than group one.

CONCLUSION

This study confirms that the combined use of mifepristone and misoprostol is a safe and effective way of managing IUD after 24 weeks gestation. Regimen one results in a shorter induction to delivery interval but is associated with a higher incidence of gastrointestinal side-effects.

Comparison of oral and vaginal misoprostol for induction of labor at term: A randomized controlled trial

OBJECTIVE

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

METHODS

One hundred and fifty-three pregnant women at term with indications for induction of labor and Bishop score < or = 6 were randomly assigned to receive misoprostol either 100 microg orally or 50 microg vaginally every 6 h for 48 h. Repeated doses were given until Bishop score > or = 8 was achieved or spontaneous rupture of membranes occurred. Those who were not in labor after 48 h had labor induced with amniotomy and oxytocin. The main outcome measure was induction to delivery time.

RESULTS

The median induction to vaginal delivery time in the oral group (14.3 h) was not significantly different from that of the vaginal group (15.8 h). The median number of doses was also not significantly different in the oral group compared with the vaginal group. There was a significant higher incidence of uterine tachysystole in the vaginal group compared to the oral group (17.1% vs 5.3%, P = 0.032). There was no hyperstimulation in either group. There were no significant differences between the groups with respect to oxytocin augmentation, cesarean section rate, analgesic requirement, and neonatal outcomes.

CONCLUSION

Oral administration of 100 microg misoprostol has similar efficacy to intravaginal administration of 50 microg misoprostol for labor induction with less frequent abnormal uterine contractility. 100 microg of misoprostol orally can be used as an alternative to the vaginal route for labor induction.

A comparison of orally administered misoprostol to intravenous oxytocin for labor induction in women with favorable cervical examinations

OBJECTIVE

The purpose of this study was to compare orally administered misoprostol with intravenous oxytocin infusion for labor induction in women with favorable cervical examinations (defined as a Bishop score of 6 or more).

STUDY DESIGN

One hundred ninety-eight women with indications for labor induction and favorable cervical examinations were assigned randomly to receive oral misoprostol or oxytocin induction. Misoprostol, 100 mg, was administered every 4 hours up to 6 doses, or intravenous oxytocin was administered by standardized protocol.

RESULTS

One hundred ten (55.6%) women received misoprostol; 88 (44.4%) received intravenous oxytocin. There was no statistically significant difference in the average interval from start of induction to vaginal delivery, being longer in the misoprostol group (789.4 +/- 510.2 minutes) than in the oxytocin group (654.0 +/- 338.2 minutes, P=.19, log-transformed data). Two women had tachysystole develop in each treatment group. More women in the misoprostol group experienced hyperstimulation (7/110, 6.4%) than in the oxytocin group (0/88, P=.02, Fisher exact test). Nine (8.1%) misoprostol-treated women and 8 (9.1%) oxytocin-treated women underwent cesarean deliveries (P=.82). There was a presumed uterine rupture in a misoprostol-treated multipara women. There were no statistically significant differences in neonatal outcomes between the groups.

CONCLUSION

Oral misoprostol offers no benefit over intravenous oxytocin for labor induction in women with favorable cervical examinations. It is associated with a higher likelihood of uterine hyperstimulation and may increase the risk of uterine rupture.

Induction of labour with a favourable cervix and/or pre-labour rupture of membranes

Premature rupture of membranes (PROM) occurs in 8% of term deliveries. In this situation labour induction with prostaglandins, compared with expectant management, results in a reduced risk of chorioamnionitis, neonatal antibiotic therapy, neonatal intensive care (NICU) admission, and increased maternal satisfaction. The use of prostaglandin is associated with an increased rate of diarrhoea and use of analgesia/anaesthesia. Compared with oxytocin, prostaglandin induction results in a lower rate of epidural use and internal fetal heart rate monitoring but a greater risk of chorioamnionitis, nausea, vomiting, more vaginal examinations, neonatal antibiotic therapy, NICU admission and neonatal infection. Women should be informed of the risks and benefits of each method of induction.Misoprostol is gaining increasing interest as an alternative induction agent. It appears to be an effective method of labour induction with term PROM. Further research is needed to identify the preferred dosage, route and interval of administration, and to assess uncommon maternal and neonatal outcomes. There has been limited research on the use of prostaglandins, including misoprostol, for induction of labour with a favourable cervix and intact membranes. Compared with intravenous oxytocin (with and without amniotomy), labour induction using vaginal prostaglandins in women with a favourable cervix (with and without PROM) results in a higher rate of vaginal delivery within 24 hours and increased maternal satisfaction. In women with a favourable cervix, artificial rupture of membranes followed by oral misoprostol has similar time to vaginal delivery compared with artificial rupture of membranes followed by oxytocin. Further research with prostaglandins, including misoprostol, is needed to evaluate other maternal and neonatal outcomes in women being induced with a favourable cervix. No form of prostaglandin induction in women with PROM or favourable cervix has proven clearly superior to oxytocin infusion.

Misoprostol versus oxytocin for labor induction in term and post-term pregnancy: randomized controlled trial

CONTEXT

Misoprostol, a synthetic E1 methyl analog prostaglandin, is at present receiving attention as a cervical modifier and labor induction agent. However, there is still a need for better determination of its safety and effectiveness.

OBJECTIVE

To compare intravaginal misoprostol versus intravenous oxytocin for cervical ripening and labor induction in pregnant women with unripe cervices.

DESIGN

Randomized controlled trial.

SETTING

The study was performed at the Leonor Mendes de Barros Maternity Hospital between November 1998 and December 2000.

PARTICIPANTS

210 pregnant women with intact membranes and indication for labor induction were selected.

PROCEDURES

The women randomly received 25 g of vaginal misoprostol every 4 hours, not exceeding 8 doses (105 women), or oxytocin in a continuous infusion (105 women).

MAIN MEASUREMENTS

The main parameters measured were: latent period, time from induction to vaginal delivery, delivery route, occurrence of vaginal delivery with time, occurrence of uterine tonus alterations, hypoxia and neonatal morbidity. To verify the statistical significance of the differences between the groups, the chi-squared, Student t and log-rank tests were used.

RESULTS

There were no significant differences between the groups concerning conditions for labor induction, age, parity, race, marital status, family income, initial Bishop Index and number of prenatal visits. The cesarean section rate, latent period and period from induction to vaginal delivery were significantly lower for the misoprostol group. With regard to uterine tonus alterations, tachysystole was significantly more common in the misoprostol group. However, there was no difference in hypoxia and neonatal morbidity between the groups.

CONCLUSION

25 g of misoprostol used vaginally every 4 hours is safer and more efficient for cervical ripening and labor induction than oxytocin.

A comparison between intravaginal and oral misoprostol for labor induction: a randomized controlled trial

AIM

To compare the effectiveness and safety between intravaginal and oral misoprostol for labor induction.

METHODS

One hundred and six pregnant women at term with unfavorable cervix (Bishop score < or = 4) and no contraindication to prostaglandin therapy were randomized to receive either intravaginal misoprostol 50 microg every 4 h or oral misoprostol 50 microg every 4 h for prospective randomized controlled trial study. Treatment interval from induction to vaginal delivery, maternal and neonatal complications were the main outcome measures.

RESULTS

There were no statistical differences of baseline characteristics and Bishop score prior to intervention between both groups. Time interval from induction to vaginal delivery in the oral group was slightly, but significantly, longer than that of the intravaginal group (886.1 +/- 443.5 min vs 637.0 +/- 373.3 min, respectively.) Additionally, the number of doses required was significantly higher in the oral group. Nonetheless, there was no significant difference between both groups with regard to failure of induction and maternal-neonatal complications.

CONCLUSION

The effectiveness in terms of failed induction and safety were comparable between intravaginal and oral misoprostol, but intravaginal route was better with respect to treatment interval and number of required doses. Both routes of administration can alternatively be used for labor induction.

Oral misoprostol or vaginal dinoprostone for labor induction: a randomized controlled trial

OBJECTIVE

The objective of the study was to compare the effectiveness, safety, and side effects of low-dose oral misoprostol with vaginal dinoprostone for cervical ripening and labor induction.

STUDY DESIGN

Women with Bishop score 6 or less admitted for labor induction at term were eligible for this randomized controlled trial. Exclusion criteria were multiple pregnancy, breech, fetal distress, or previous uterine scar. The allocation to the oral misoprostol group (20 microg given every 2 hours increased to 40 microg depending on uterine contractions) or to the vaginal dinoprostone group (2 mg twice, 6 hours apart) was contained in a sealed, opaque, and consecutively numbered envelope.

RESULTS

Two hundred women (100 in each group) were included. The proportion of vaginal delivery within 24 hours was 56% in the misoprostol group and 62% in the dinoprostone group (relative risk 0.90, 95% CI 0.72-1.14). The risk of cesarean section was 18% and 19%, respectively. The median interval to delivery, calculated from survival analysis, was longer in the misoprostol group (1305 minutes) compared with the dinoprostone group (1080 minutes). The log-rank test was not significant (P =.35). Uterine hyperstimulation occurred in 9% of women in the misoprostol group compared with 14% in the dinoprostone group (P =.27). The only significant difference in neonatal outcomes was a more frequent presence of thick meconium in the misoprostol group (P =.03).

CONCLUSION

We found no difference in terms of effectiveness and safety between low-dose oral misoprostol and vaginal dinoprostone used for induction of labor. This regimen avoids the excessive uterine contractility noted in previous studies, where higher doses of misoprostol were administered at longer intervals.

A comparison of vaginally administered misoprostol with extra-amniotic saline solution infusion for cervical ripening and labor induction

OBJECTIVE

The purpose of this study was to compare intravaginal misoprostol with extra-amniotic saline solution infusion with concomitant oxytocin for cervical ripening and labor induction in viable pregnancies.

STUDY DESIGN

Two hundred women with indications for labor induction and unfavorable cervices were assigned randomly to vaginal misoprostol or extra-amniotic saline solution infusion. Twenty-five micrograms of misoprostol was administered every 4 hours up to six doses, followed by intravenous oxytocin administration. Patients who had received extra-amniotic saline solution infusion also received intravenous oxytocin along with a maximum 12-hour saline solution infusion through Foley catheters that were placed above the internal cervical os.

RESULTS

One hundred women were randomly assigned to misoprostol, and 100 women were assigned randomly to extra-amniotic saline solution infusion. The average interval from start of induction to vaginal delivery was longer in the misoprostol group (1323.3 +/- 700.3 minutes) than in the extra-amniotic saline solution infusion group (970.4 +/- 502.7 minutes; P =.006, log transformed data). Abnormal fetal heart rate tracings were found in 30% of the patients who received misoprostol and in 19% of the patients who received extra-amniotic saline solution infusion (relative risk, 1.6; 95% CI, 1.0-2.4; P =.05). There was more tachysystole in the misoprostol group (8%) than in the extra-amniotic saline solution infusion group (1%; P =.02). There were no differences in the routes of deliveries or neonatal outcomes between groups.

CONCLUSION

Extra-amniotic saline solution infusion with oxytocin administration appears more effective and is associated with fewer maternal complications than misoprostol for cervical ripening and labor induction.

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.

Cervical ripening and induction of labor with misoprostol, dinoprostone gel, and a Foley catheter: a randomized trial of 3 techniques

OBJECTIVE

The purpose of this study was to compare the efficacy of 3 different techniques of cervical ripening and induction.

STUDY DESIGN

Patients who required cervical ripening and induction were randomized to one of 3 groups: (1) supracervical Foley catheter and intravaginal dinoprostone gel, (2) supracervical Foley catheter and 100 microg oral doses of misoprostol, or (3) serial 100-microg oral doses of misoprostol. Intravenous oxytocin was administered when a protraction disorder of labor was identified.

RESULTS

There were 339 women randomized. There was no significant difference in the time from first intervention to delivery in the 3 groups (P =.546). In each group, a similar percentage of women required oxytocin (P =.103). The rates of cesarean delivery were equivalent among the groups (P =.722). Rates of tachysystole were high but statistically equivalent among the 3 groups. There were no significant differences in Apgar scores or umbilical artery pH.

CONCLUSION

Oral 100 microg serial doses of misoprostol, with or without the use of a supracervical Foley catheter, were equivalent to the use of a supracervical Foley catheter and serial 4-mg doses of dinoprostone gel for cervical ripening and the induction of labor.

Factors affecting the likelihood of successful induction after intravaginal misoprostol application for cervical ripening and labor induction

OBJECTIVE

Our purpose was to determine whether maternal age, height and weight, parity, duration of pregnancy, cervical dilatation or Bishop score, and birth weight could be used to predict the likelihood of successful induction in women given intravaginal misoprostol.

STUDY DESIGN

A computerized database was compiled of 1373 pregnancies in which intravaginal misoprostol was given for cervical ripening and labor induction. Most of these women were placed on investigational protocols in which the dose of misoprostol administered was 25 to 50 microg and the dosing intervals ranged from 3 to 6 hours. No more than 24 hours of administration was permitted. Induction was undertaken in women with unfavorable cervical examinations (Bishop scores of 4 or less) and without spontaneous labor or ruptured membranes. Univariate and stepwise multiple regression analyses were performed to identify those factors associated with successful induction, defined as vaginal delivery within 24 hours of induction.

RESULTS

Six hundred fifty-seven (48%) had successful induction. Parity (odds ratio [OR] 2.5, 95% CI 2.0-2.9, P <.0001), initial cervical dilatation (OR 1.9, 95% CI 1.6-2.3, P <.0001), Bishop score (OR 1.6, 95% CI 1.3, 1.8, P <.0001), and gestational age at entry (OR 1.3, 95% CI 1.1-1.5, P =.002) were significant at the.05 level for predicting successful induction. A multivariate stepwise logistic regression was then performed to evaluate each of these as independent predictors. Parity (OR 2.4, 95% CI 2.0-3.0, P <.0001), initial cervical dilatation (OR 1.7, 95% CI 1.4-2.1, P <.0001), and estimated gestational age (OR 1.3, 95% CI 1.1-1.6, P =.003) are significant independent predictors for successful induction, but initial Bishop score is not significant (P =.19) after adjustment for other significant predicting factors.

CONCLUSIONS

The clinical characteristics of parity, initial cervical dilatation, and gestational age at entry are predictors of the likelihood of success of cervical ripening and labor induction with intravaginal misoprostol administration.