Two dosing regimens for preinduction cervical priming with intravaginal dinoprostone pessary: a randomised clinical trial

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.

Maternal and neonatal outcomes following additional doses of vaginal prostaglandin E2 for induction of labour: a retrospective cohort study

OBJECTIVE

To assess maternal and neonatal outcomes following the use of additional doses of vaginal prostaglandins (PGE2) above the recommended dose for induction of labour in post-dates pregnancies.

STUDY DESIGN

Retrospective cohort study set in Aberdeen Maternity Hospital, Aberdeen, UK. A total of 3514 nulliparous women with labour induced with vaginal PGE2 (3mg tablet or 2mg gel) for a post-dates singleton pregnancy from January 1994 to December 2009 were included. Women receiving≤2 doses of PGE2 were compared with those receiving>2 doses (maximum 5 doses). Binary logistic regression was used to calculate odds ratios (OR) with 95% confidence intervals (CI). Primary outcomes included mode of delivery, terbutaline use, indication for CS, postpartum haemorrhage, neonatal unit admission, and Apgar score<7. A further analysis was conducted which stratified for number of doses of PGE2 given.

RESULTS

Of the 3514 women who met inclusion criteria, 605 (17%) received PGE2 that exceeded the licensed dose. They were more likely to deliver by caesarean section (53.4% vs. 31.8%, OR 2.2, 95% CI 1.8-2.6), have a caesarean section for 'failed' induction of labour (11.4% vs. 1.9%, OR 4.1, 95% CI 1.3-13.2) or lack of progress in labour (37% vs. 17%, OR 2.8, 95% CI 2.3-3.4), but not for fetal concerns (8.2% vs. 8.8% OR 0.9, 95% CI 0.7-1.3). Terbutaline use and postpartum haemorrhage was no more likely (0.7% vs. 0.9% OR 0.6 95% CI 0.3-1.5 and 19.8% vs. 18.9% OR1.01, 95% CI 0.97-1.06 respectively). Apgar score<7 (1.1% vs. 1.3% OR 0.9 95% CI 0.8-1.1) and neonatal unit admission (13.7% vs. 10.7% OR 1.2 95% CI 0.8-1.6) were similar in both groups.

CONCLUSION

The use of additional doses of vaginal PGE2 above the recommended dose for induction of labour was not associated with increased maternal or neonatal morbidity and almost half of these women achieved a vaginal delivery.

Shortening the induction delivery interval with prostaglandins: a randomized controlled trial of solo or in combination

OBJECTIVE

To compare the efficacy and safety of misoprostol alone with dinoprostone followed by misoprostol, all inserted intravaginally in induction of labor at term and the obstetrical outcome.

MATERIAL AND METHODS

A pilot study comprising 111 primigravidae, >37 gestational weeks with singleton pregnancy in cephalic presentation having an unfavorable Bishop score admitted for labor induction, were considered and randomly allocated into two groups. In group I (n=55) with intravaginal 25mcg misoprostol 4 hourly (six doses at the most) and and group II (n=56), with dinoprostone 0.5mg followed eight hours later by 25mcg misoprostol induction to vaginal delivery time was found to be significantly different, being 14.8 h in group-I and shorter in group-II with a mean of 11.6 h. Vaginal delivery rates within 12 h (groups-I and -II: 47.2%, as compared to 60.7%, respectively) were found to be higher with dinoprostone-misoprostol induction, as well as vaginal delivery rates in 24 h, 80.0% and 91.1%. The need for oxytocin augmentation was more frequent in the misoprostol than in the dinoprostone-misoprostol group, (61.8%, and 39.3%), and all these observations were statistically significant. Abnormal foetal heart rate pattern occurred more frequently (18.2%) in group-I in contrast to 5.3% in group-II, as was the incidence rate of (18.2%) who had passage of meconium in group-I, this rate being significantly different from group-II having meconium passage in 3 cases, a rate of 5.3%.

CONCLUSION

Using dinoprostone followed by vaginal misoprostol is safe and effective for induction of labor with less need for oxytocin augmentation and shorter induction delivery interval.

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.

The cost-effectiveness of outpatient (at home) cervical ripening with isosorbide mononitrate prior to induction of labour

OBJECTIVES

To assess the cost-effectiveness of outpatient (at home) cervical ripening with isosorbide mononitrate (IMN) prior to induction of labour.

DESIGN

Economic evaluation was conducted alongside a randomised placebo controlled trial (the IMOP trial).

SETTING

Large UK maternity hospital.

POPULATION

A total of 350 nulliparous women with a singleton pregnancy, cephalic presentation > or = 37 weeks gestation, requiring cervical ripening prior to induction of labour.

INTERVENTIONS

Isosorbide mononitrate (n = 177) or placebo (n = 173) self-administered vaginally at home at 48, 32 and 16 hours prior to the scheduled time of admission for induction.

RESULTS

Mean health service costs between the period of randomisation and discharge for mother and infant were 1254.86 pound sterling in the IMN group and 1242.88 pound sterling in the placebo group, generating a mean cost difference of 11.98 pound sterling (bootstrap mean cost difference 12.86 pound sterling; 95%CI: -106.79 pound sterling, 129.39 pound sterling) that was not statistically significant (P = 0.842). The incremental cost per hour prevented from hospital admission to delivery was 7.53 pound sterling. At the notional willingness to pay threshold of 100 pound sterling per hour prevented from hospital admission to delivery, the probability that IMN is cost-effective was estimated at 0.67. This translated into a mean net monetary benefit of 98.13 pound sterling for each woman given IMN.

CONCLUSIONS

Although the probability that IMN is cost-effective approaches 0.7 at seemingly low willingness to pay thresholds for an hour prevented from hospital admission to delivery, our results should be viewed in the light of the clinical findings from the IMOP trial.

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.

Labor induction

Labor induction has become commonplace in modern obstetrics. The increasing rate of labor induction has probably played a role in the increased rate of cesarean delivery observed in the United States during the past few decades. Clearly, the favorability of the cervix has a substantial impact on the potential success of any labor induction. Induction in the setting of an unfavorable cervix can result in prolonged induction, prolonged hospitalization, failed induction, and an increased cesarean delivery rate. In this modern era of healthcare reform and cost containment, the identification of therapeutic strategies to enhance the success and cost-effectiveness of labor induction are of great interest. Ongoing research is needed to advance our knowledge of the mechanisms of parturition and cervical ripening in order to direct interventions for labor induction more effectively.