Induction of labor with intravaginal prostaglandin E2 gel

Twice-daily versus once-daily vaginal dinoprostone gel for induction of labor at term: A randomized controlled trial

OBJECTIVE

The aim of this study was to compare twice-daily versus once-daily administration of intravaginal PGE2 for induction of labor at term. Efficacy, safety, and patient satisfaction were evaluated.

STUDY DESIGN

For this single-center, randomized, comparative, open-label, two-arm, and parallel study, pregnant women with term singleton live pregnancies ≥ 37 weeks of gestation, medical indications for induction of labor, and Bishop score ≤ 6 were randomized to either the control group (induction of labor with PGE2 gel with repeat dose after 24 h) or the experimental group (repeat dose after 12 h). The primary outcome was induction-to-delivery interval time. Secondary outcomes were maternal and neonatal outcomes and patient satisfaction.

RESULTS

In total, 246 women were randomized to the control (n = 121) or experimental groups (n = 125). The mean time for initiation of induction to delivery was 9.4 h shorter in the experimental group compared to controls (p = 0.007). For control vs experimental, there were no differences in tachysystole (19/121, 15.7 % vs 21/124, 16.9 %, respectively; p = 0.79), cesarean section rate (18/121, 14.9 % vs 28/124, 22.6 % respectively; p = 0.12), or other main obstetrical or neonatal outcomes. Patients in the experimental group reported higher satisfaction with their induction (48/96, 50 % with once-daily vs 60/86, 69.8 % with twice-daily; p = 0.010).

CONCLUSION

Among women admitted for induction of labor at term, closer interval of vaginal PGE2 administration was associated with a significantly shorter induction-to-delivery time without increasing maternal or neonatal morbidity. Furthermore, the reduction in induction time was associated with improved patient experience of delivery.

Vaginal prostaglandin (PGE2 and PGF2a) for induction of labour at term

BACKGROUND

Prostaglandins have been used for induction of labour since the 1960s. This is one of a series of reviews evaluating methods of induction of labour. This review focuses on prostaglandins given per vaginam, evaluating these in comparison with placebo (or expectant management) and with each other; prostaglandins (PGE2 and PGF2a); different formulations (gels, tablets, pessaries) and doses.

OBJECTIVES

To determine the effects of vaginal prostaglandins E2 and F2a for third trimester cervical ripening or induction of labour in comparison with placebo/no treatment or other vaginal prostaglandins (except misoprostol).

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (1 March 2014) and bibliographies of relevant papers.

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

We assessed studies and extracted data independently.

MAIN RESULTS

Seventy randomised controlled trials (RCTs) (11,487 women) are included. In this update seven new RCTs (778 women) have been added. Two of these new trials compare PGE2 with no treatment, four compare different PGE2 formulations (gels versus tablets, or sustained release pessaries) and one trial compares PGF2a with placebo. The majority of trials were at unclear risk of bias for most domains.Overall, vaginal prostaglandin E2 compared with placebo or no treatment probably reduces the likelihood of vaginal delivery not being achieved within 24 hours. The risk of uterine hyperstimulation with fetal heart rate changes is increased (4.8% versus 1.0%, risk ratio (RR) 3.16, 95% confidence interval (CI) 1.67 to 5.98, 15 trials, 1359 women). The caesarean section rate is probably reduced by about 10% (13.5% versus 14.8%, RR 0.91, 95% CI 0.81 to 1.02, 36 trials, 6599 women). The overall effect on improving maternal and fetal outcomes (across a variety of measures) is uncertain.PGE2 tablets, gels and pessaries (including sustained release preparations) appear to be as effective as each other, small differences are detected between some outcomes, but these maybe due to chance.

AUTHORS' CONCLUSIONS

Prostaglandins PGE2 probably increase the chance of vaginal delivery in 24 hours, they increase uterine hyperstimulation with fetal heart changes but do not effect or may reduce caesarean section rates. They increase the likelihood of cervical change, with no increase in operative delivery rates. PGE2 tablets, gels and pessaries appear to be as effective as each other, any differences between formulations are marginal but may be important.

Vaginal prostaglandin (PGE2 and PGF2a) for induction of labour at term

BACKGROUND

Prostaglandins have been used for induction of labour since the 1960s. Initial work focused on prostaglandin F2a as prostaglandin E2 was considered unsuitable for a number of reasons. With the development of alternative routes of administration, comparisons were made between various formulations of vaginal prostaglandins.

OBJECTIVES

To determine the effects of vaginal prostaglandins E2 and F2a for third trimester cervical ripening or induction of labour in comparison with placebo/no treatment or other vaginal prostaglandins (except misoprostol).

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (May 2009) and bibliographies of relevant papers.

SELECTION CRITERIA

Clinical trials comparing vaginal prostaglandins 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 assessed studies and extracted data independently.

MAIN RESULTS

Sixty-three (10,441 women) have been included.Vaginal prostaglandin E2 compared with placebo or no treatment reduced the likelihood of vaginal delivery not being achieved within 24 hours (18.1% versus 98.9%, risk ratio (RR) 0.19, 95% confidence interval (CI) 0.14 to 0.25, two trials, 384 women). The risk of the cervix remaining unfavourable or unchanged was reduced (21.6% versus 40.3%, RR 0.46, 95% CI 0.35 to 0.62, five trials, 467 women); and the risk of oxytocin augmentation reduced (35.1% versus 43.8%, RR 0.83, 95% CI 0.73 to 0.94, 12 trials, 1321 women) when PGE2 was compared to placebo. There was no evidence of a difference between caesarean section rates, although the risk of uterine hyperstimulation with fetal heart rate changes was increased (4.4% versus 0.49%, RR 4.14, 95% CI 1.93 to 8.90, 14 trials, 1259 women).PGE2 tablet, gel and pessary appear to be as efficacious as each other and the use of sustained release PGE2 inserts appear to be associated with a reduction in instrumental vaginal delivery rates (9.9 % versus 19.5%, RR 0.51, 95% CI 0.35 to 0.76, NNT 10 (6.7 to 24.0), five trials, 661 women) when compared to vaginal PGE2 gel or tablet.

AUTHORS' CONCLUSIONS

PGE2 increases successful vaginal delivery rates in 24 hours and cervical favourability with no increase in operative delivery rates. Sustained release vaginal PGE2 is superior to vaginal PGE2 gel with respect to some outcomes studied.Further research is needed to assess the best vehicle for delivering vaginal prostaglandins and this should, where possible, include some examination of the cost-analysis.

Vaginal prostaglandin (PGE2 and PGF2a) for induction of labour at term

BACKGROUND

Prostaglandins have been used for induction of labour since the 1960s. Initial work focused on prostaglandin F2a as prostaglandin E2 was considered unsuitable for a number of reasons. With the development of alternative routes of administration, comparisons were made between various formulations of vaginal prostaglandins. 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 prostaglandins E2 and F2a for third trimester cervical ripening or induction of labour in comparison with placebo/no treatment or other vaginal prostaglandins (except misoprostol).

SEARCH STRATEGY

The Cochrane Pregnancy and Childbirth Group trials register (May 2003) and bibliographies of relevant papers.

SELECTION CRITERIA

Clinical trials comparing vaginal prostaglandins 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

A strategy was developed to deal with the large volume and complexity of trial data relating to labour induction. This involved a two-stage method of data extraction.

MAIN RESULTS

In total, 101 studies were considered: 43 excluded and 57 (10,039 women) included. One study is awaiting assessment. Vaginal prostaglandin E2 compared with placebo or no treatment reduced the likelihood of vaginal delivery not being achieved within 24 hours (18% versus 99%, relative risk (RR) 0.19, 95% confidence interval (CI) 0.14 to 0.25, 2 trials, 384 women), there was no evidence of a difference between caesarean section rates although the risk of uterine hyperstimulation with fetal heart rate changes was increased (4.6% versus 0.51%, RR 4.14, 95% CI 1.93 to 8.90, 13 trials, 1203 women). Comparison of vaginal prostaglandin F2a with placebo showed similar caesarean section rates but the cervical score was more likely to be improved (15% versus 60%, RR 0.25, 95% CI 0.13 to 0.49, 5 trials, 467 women), and the risk of oxytocin augmentation reduced (53.9% versus 89.1%, RR 0.60, 95% CI 0.43 to 0.84, 11 trials, 1265 women) with the use of vaginal PGF2a. There were insufficient data to make meaningful conclusions for the comparison of vaginal PGE2 and PGF2a.PGE2 tablet, gel and pessary appear to be as efficacious as each other. Lower dose regimens, as defined in the review, appear as efficacious as higher dose regimens.

REVIEWER'S CONCLUSIONS

The primary aim of this review was to examine the efficacy of vaginal prostaglandin E2 and F2a. This is reflected by an increase in successful vaginal delivery rates in 24 hours, no increase in operative delivery rates and significant improvements in cervical favourability within 24 to 48 hours. Further research is needed to quantify the cost-analysis of induction of labour with vaginal prostaglandins, with special attention to different methods of administration.

Comparison of labor induction with misoprostol vs. oxytocin/prostaglandin E2 in term pregnancy

OBJECTIVE

To compare the efficacy and safety of intravaginal and oral misoprostol vs. oxytocin/prostaglandin E2 (PGE2) gel for third trimester labor induction.

METHODS

Two hundred twenty-four pregnant women were randomized to induction of labor either with misoprostol or oxytocin and PGE2 gel. Patients in the misoprostol group (n = 112) received 100 micrograms intravaginal misoprostol followed by 100 micrograms p.o. every 2 h. The oxytocin/PGE2 group consisted of 112 patients who underwent PGE2 cervical instillation 6 h before continuous oxytocin infusion. The perinatal, intrapartum and neonatal characteristics of both groups were determined.

RESULTS

Induction to active phase of labor was successfully achieved in 96 women (85.7%) in the misoprostol group vs. 86 women (76.8%) in the oxytocin/PGE2 group, but the drug initiation-delivery interval was significantly shorter in the misoprostol group (9.2 +/- 2.4 h) than in the oxytocin/PGE2 group (15.2 +/- 3.2 h, P < 0.001). The incidence of adverse intrapartum outcomes was similar for both methods. Intravaginal misoprostol 100 micrograms followed by a single oral dose of 100 micrograms misoprostol safely produced labor and a vaginal delivery in 70% of patients. More than three tablets were required in only 10% of patients. There was a higher prevalence of cesarean section for failed induction in the oxytocin/PGE2 group than in the misoprostol group (13.4 vs. 6.3%, P < 0.001). The neonatal outcomes of both groups were also similar.

CONCLUSION

Misoprostol is significantly more effective for labor induction than oxytocin/PGE2 gel. The maternal intrapartum and neonatal outcomes were the same for both induction regimens. From a clinical and perinatal perspective, misoprostol is an acceptable choice for labor induction.

Preinduction cervical ripening with intravaginal prostaglandin E1 methyl analogue misoprostol: a randomized controlled trial

OBJECTIVE

To evaluate the efficacy of intravaginal prostaglandin E1 methyl analogue misoprostol in cervical ripening in patients with unfavorable cervix (Bishop score < 4) requiring labor induction.

METHOD

A randomized controlled clinical trial of 62 women in the third trimester with various indications for induction of labor were randomly allocated to receive either 100 micrograms misoprostol inserted vaginally (32) or placebo similarly applied (30). Transvaginal sonography was performed to measure the cervical length before and 12 hrs after insertion.

RESULTS

The mean change in cervical length and Bishop score was significantly greater in the misoprostol group (24 mm and score 8) compared with in the placebo group (2.2 mm and score 1) (p = 0.001). All but one patients receiving misoprostol went into labor while only one in the placebo group did so. The interval from insertion to vaginal delivery was significantly shorter in the misoprostol group (12.0 vs 25.5 hrs, p < 0.001). Delivery occurred within 24 hrs in 75% and 30% of patients in the misoprostol and placebo groups respectively. Uterine tachsystole occurred more frequently in the misoprostol group (38%) than in the placebo group (0%) (p < 0.001). All could be rapidly reversed by tocolytics without apparent untoward intrapartum effects. No significant differences were noted in the 2 groups in terms of perinatal outcomes and mode of delivery.

CONCLUSION

Intravaginal misoprostol is an effective, cheap and safe method for cervical ripening. The higher frequency of uterine tachysystole in the misoprostol group did not increase the risk of adverse intrapartum and neonatal outcomes.

Efficacy of outpatient induction with low-dose intravaginal prostaglandin E2: a randomized, double-blind, placebo-controlled trial

OBJECTIVE

Our purpose was to determine whether a protocol for outpatient induction is safe and effective for initiating labor.

STUDY DESIGN

A randomized, double-blind, placebo-controlled trial was performed with 100 low-risk patients having well-dated pregnancies. Women with a Bishop score < or = 6 at 38 to 40 weeks' gestation were administered either 2 mg of intravaginal prostaglandin E2 gel or placebo for 5 consecutive days as outpatients while undergoing fetal monitoring.

RESULTS

The median interval from randomization to delivery was 4 days in the prostaglandin E2 group (range 0 to 28 days) versus 10 days in the placebo group (range 0 to 26 days, p = 0.002). Twenty-seven of 50 patients (54%) in the prostaglandin E2 group were admitted for labor during the dosing interval compared with 10 placebo-treated patients (20%, p = 0.001). The mean gestational age at delivery was significantly reduced in the treatment group (39.9 +/- 1.0 weeks vs 40.5 +/- 0.99 weeks, p = 0.003) as was the incidence of postdates pregnancy (40% vs 66%, p = 0.016). Hyperstimulation was observed in one prostaglandin E2-treated patient, but no intervention was required.

CONCLUSIONS

Outpatient low-dose prostaglandin E2 gel administration is effective for initiating labor in patients with an unfavorable cervix and appears safe if performed with adequate monitoring.