Induction of labor with three different techniques at 41 weeks of gestation or spontaneous follow-up until 42 weeks in women with definitely unfavorable cervical scores

Do mechanical methods of cervical ripening increase infectious morbidity? A systematic review

The purpose of this study was to review systematically randomized controlled trials that were associated with cervical ripening. We identified randomized controlled trials that compared the use of Foley catheter, with or without extraamniotic saline solution infusion, Laminaria, or hygroscopic dilators for cervical ripening or induction with pharmacologic agents or placebo. Randomized controlled trials that evaluated maternal or neonatal infection were selected. The outcomes that were assessed were maternal and neonatal infection, chorioamnionitis, and endomyometritis. Thirty studies met inclusion criteria. Compared with the use of pharmacologic methods alone, patients who underwent cervical ripening with mechanical agents had a significantly higher rate of maternal infection rates. Similar results were noted for patients who underwent ripening with Foley catheter alone in comparison with pharmacologic agents. No difference was noted in maternal infection rates for patients who underwent ripening with extraamniotic saline solution infusion, Laminaria, or hygroscopic dilators. Compared with the use of pharmacologic agents alone, maternal and neonatal infectious morbidity appears to be increased when mechanical agents are used for cervical ripening.

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 labour for improving birth outcomes for women at or beyond term

BACKGROUND

As a pregnancy continues beyond term the risks of babies dying inside the womb or in the immediate newborn period increase. Whether a policy of labour induction at a predetermined gestational age can reduce this increased risk is the subject of this review.

OBJECTIVES

To evaluate the benefits and harms of a policy of labour induction at term or post-term compared to awaiting spontaneous labour or later induction of labour.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (June 2006).

SELECTION CRITERIA

Randomized controlled trials conducted in women at or beyond term. The eligible trials were those comparing a policy of labour induction to a policy of awaiting spontaneous onset of labour. Trials comparing cervical ripening methods, membrane stripping/sweeping or nipple stimulation without any commitment to delivery within a certain time were excluded.

DATA COLLECTION AND ANALYSIS

Two review authors independently evaluated potentially eligible trials and extracted data. Outcomes are analysed in two main categories: gestational age and cervix status.

MAIN RESULTS

We included 19 trials reporting on 7984 women. A policy of labour induction at 41 completed weeks or beyond was associated with fewer (all-cause) perinatal deaths (1/2986 versus 9/2953; relative risk (RR) 0.30; 95% confidence interval (CI) 0.09 to 0.99). The risk difference is 0.00 (95% CI 0.01 to 0.00). If deaths due to congenital abnormality are excluded, no deaths remain in the labour induction group and seven deaths remain in the no-induction group. There was no evidence of a statistically significant difference in the risk of caesarean section (RR 0.92; 95% CI 0.76 to 1.12; RR 0.97; 95% CI 0.72 to 1.31) for women induced at 41 and 42 completed weeks respectively. Women induced at 37 to 40 completed weeks were more likely to have a caesarean section with expectant management than those in the labour induction group (RR 0.58; 95% CI 0.34 to 0.99). There were fewer babies with meconium aspiration syndrome (41+: RR 0.29; 95% CI 0.12 to 0.68, four trials, 1325 women; 42+: RR 0.66; 95% CI 0.24 to 1.81, two trials, 388 women).

AUTHORS' CONCLUSIONS

A policy of labour induction after 41 completed weeks or later compared to awaiting spontaneous labour either indefinitely or at least one week is associated with fewer perinatal deaths. However, the absolute risk is extremely small. Women should be appropriately counselled on both the relative and absolute risks.