Prostaglandin E2 gel for cervical ripening in patients with an indication for delivery

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.

Use of labour induction and risk of cesarean delivery: a systematic review and meta-analysis

BACKGROUND

Induction of labour is common, and cesarean delivery is regarded as its major complication. We conducted a systematic review and meta-analysis to investigate whether the risk of cesarean delivery is higher or lower following labour induction compared with expectant management.

METHODS

We searched 6 electronic databases for relevant articles published through April 2012 to identify randomized controlled trials (RCTs) in which labour induction was compared with placebo or expectant management among women with a viable singleton pregnancy. We assessed risk of bias and obtained data on rates of cesarean delivery. We used regression analysis techniques to explore the effect of patient characteristics, induction methods and study quality on risk of cesarean delivery.

RESULTS

We identified 157 eligible RCTs (n = 31,085). Overall, the risk of cesarean delivery was 12% lower with labour induction than with expectant management (pooled relative risk [RR] 0.88, 95% confidence interval [CI] 0.84-0.93; I(2) = 0%). The effect was significant in term and post-term gestations but not in preterm gestations. Meta-regression analysis showed that initial cervical score, indication for induction and method of induction did not alter the main result. There was a reduced risk of fetal death (RR 0.50, 95% CI 0.25-0.99; I(2) = 0%) and admission to a neonatal intensive care unit (RR 0.86, 95% CI 0.79-0.94), and no impact on maternal death (RR 1.00, 95% CI 0.10-9.57; I(2) = 0%) with labour induction.

INTERPRETATION

The risk of cesarean delivery was lower among women whose labour was induced than among those managed expectantly in term and post-term gestations. There were benefits for the fetus and no increased risk of maternal death.

Intracervical prostaglandins for induction of labour

BACKGROUND

Prostaglandins have been used for cervical ripening and induction of labour since the 1970s. The goal of the administration of prostaglandins in the process of induction of labour is to achieve cervical ripening before the onset of contractions. One of the routes of administration that was proposed is intracervical. Using this route, prostaglandins are less easy to administer and the need for exposing the cervix may cause discomfort to the woman.

OBJECTIVES

To determine the effects of intracervical prostaglandins for third trimester cervical ripening or induction of labour compared with placebo/no treatment and with vaginal prostaglandins (except misoprostol).

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (August 2007) and bibliographies of relevant papers.

SELECTION CRITERIA

Clinical trials comparing intracervical 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 (vaginal prostaglandins, except misoprostol).

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

Fifty-six trials (7738 women) are included. INTRACERVICAL PGE2 WITH PLACEBO/NO TREATMENT: 28 TRIALS, 3764 WOMEN: Four studies reported the number of women who did not achieve vaginal delivery within 24 hours, showing a decreased risk with PGE2 (relative risk (RR) 0.61; 95% confidence interval (CI) 0.47 to 0.79). There was a small, and statistically non-significant, reduction of the risk of caesarean section when PGE2 was used (RR 0.88; 95% CI 0.77 to 1.00). The finding was statistically significant in a subgroup of women with intact membranes and unfavourable cervix only (RR 0.82; 95% CI 0.68 to 0.98). The risk of hyperstimulation with fetal heart rate (FHR) changes was not significantly increased (RR 1.21; 95% CI 0.72 to 2.05). However, the risk of hyperstimulation without FHR changes was significantly increased (RR 1.59; 95% CI 1.09 to 2.33. INTRACERVICAL PGE2 WITH INTRAVAGINAL PGE2: 29 TRIALS, 3881 WOMEN: The risk of not achieving vaginal delivery within 24 hours was increased with intracervical PGE2 (RR 1.26; 95% CI 1.12 to 1.41). There was no change in the risk of caesarean section (RR 1.07; 95% CI 0.93 to 1.22). The risks of hyperstimulation with FHR changes (RR 0.76; 95% CI 0.39 to 1.49) and without FHR changes (RR 0.80; 95% CI 0.56 to 1.15) were non-significantly different with the two methods of PGE2 administration. Only one trial with small sample size reported on women's views, with no difference between groups. INTRACERVICAL PGE2 LOW DOSE WITH INTRACERVICAL PGE2 HIGH DOSE: TWO TRIALS, 102 WOMEN: The trials are too small to provide any useful information.

AUTHORS' CONCLUSIONS

Intracervical prostaglandins are effective compared to placebo, but appear inferior when compared to intravaginal prostaglandins.

Induction of labor in the absence of standard medical indications: incidence and correlates

BACKGROUND

Induction of labor is an increasingly common obstetrical procedure, with approximately 20-34% of women undergoing labor induction in the United States annually.

OBJECTIVE

To determine the extent of labor induction in the absence of standard medical indications and to assess possible associations with maternal and infant characteristics and hospital factors.

METHODS

We ascertained induction of labor and associated details as part of a medical record validation study of 4541 women with live, singleton births in 2000 in Washington State using medical record, birth certificate, and hospital discharge data. In this analysis, we report findings for the 1473 women (33% of original cohort) whose medical records indicated that their labors were induced.

RESULTS

Among women with induced labor, 7.9% had no clinical information providing an indication for the induction, and 6.4% had only "nonstandard" indications recorded. Compared with women delivering in moderate volume hospitals, women who delivered at lower volume (odds ratios [OR] 3.9; 95% confidence intervals [CI] 1.8-8.6) or higher volume hospitals (OR 4.2; 95% CI 2.4-7.2) had significantly increased risk for undocumented indication of labor. Women who had undocumented indication for induction were at significantly decreased risk of giving birth at a teaching hospital and a public nonfederally owned hospital, and were at greater risk to give birth at a private religious hospital. Factors that remained independently associated with nonstandard indication for induction of labor were primiparas (OR 2.4; 95% CI 1.3-4.2); multiparas (OR 4.3; 95% CI 2.5-7.4), pregnancy-induced hypertension (OR 0.2; 95% CI 0.1-0.4), hospital volume >or=2000 births annually (OR 19.9; 95% CI 6.7-58.6), primary (OR 11.7; 95% CI 4.1-33.6), and tertiary level hospital (OR 0.4; 95% CI 0.2-0.7).

CONCLUSIONS

Our findings suggest that nearly 15% of inductions either were not clinically indicated according to standard protocols or indications were incompletely documented. At minimum, further studies are needed to explore how best to improve documentation of indications of labor because accurately describing, among other things, the process of labor induction, is a basic benchmark of care.

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.

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

OBJECTIVE

To compare the efficacy within 24 hours of a three-times-a-day intensive dosing regimen with a standard once daily dosing regimen using dinoprostone vaginal pessary in preinduction cervical priming.

DESIGN

Randomised controlled trial.

SETTING

Department of Obstetrics and Gynaecology, Singapore General Hospital.

PARTICIPANTS

One hundred singleton term primigravidae with cephalic presentation with unfavourable cervical scores (Bishop score < or = 5) requiring induction of labour.

METHODS

Eligible women were randomly assigned the standard regimen (3000 microg dinoprostone [Prostin, Upjohn, Crawley, UK] once daily) or an intensive regimen (3000 microg dinoprostone given sequentially three times daily four hours apart) for cervical priming until successful priming (Bishop score of > or = 6) or the onset of active labour occurred.

MAIN OUTCOME MEASURES

Number of women whose cervices were ripened successfully or who entered active labour within 24 hours of starting cervical priming, priming to induction interval, and priming to delivery interval.

RESULTS

Forty-nine women were assigned to the standard regimen and 51 to the intensive regimen. The median number (range) of dinoprostone pessaries used was two (one to seven) in the standard regimen and three (one to nine) in the intensive regimen. Forty-two women (82.4%) who underwent the intensive regimen achieved successful cervical ripening or active labour within 24 hours, compared with 21 assigned to standard regimen (OR 6.2, 95% CI 2.3-17.4). This difference was statistically significant. The median intervals from priming to induction, and from priming to delivery, were also statistically significantly shorter in women treated with the intensive regimen. Thirty-five women (68.63%) assigned the intensive regimen experienced pain, compared with 21 (42.86%) in the standard regimen (OR 2.92, 95% CI 1.19-7.21), with two and one women in the respective regimens requiring opiate analgesics. Five women with oligohydramnios had transient cardiotocographic abnormalities during priming with the intensive regimen, none of which required immediate intervention, and the babies were born in good condition. There were no cases of uterine hypertonus and the outcomes of labour were similar for women from both regimens.

CONCLUSIONS

Preinduction cervical priming with the intensive dosing regimen improves the chances of successful ripening within 24 hours for primigravidae with unfavourable cervical scores at full term singleton pregnancies, and shortens the interval from priming to induction, and priming to delivery. This regimen may be more cost effective by shortening the period of hospital stay. The overall incidence of adverse reactions to the mother and fetus during priming was low. However, close fetal surveillance must be maintained, particularly in pregnancies complicated with oligohydramnios.