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.
OBJECTIVE: To systematically review and summarize the medical literature regarding the effects of expectant management and labor induction on mode of delivery and perinatal outcomes in patients with suspected fetal macrosomia.
DATA SOURCES: We supplemented a search of entries in electronic databases with references cited in original studies and review articles to identify studies assessing management of patients with suspected fetal macrosomia.
METHODS OF STUDY SELECTION: We evaluated, abstracted data, and performed quantitative analyses in studies assessing the outcome of patients with suspected fetal macrosomia. Observational studies and randomized trials were included in this systematic review.
TABULATION, INTEGRATION, AND RESULTS: Twenty-nine studies were identified, 11 of which met our criteria for systematic review and meta-analysis. These 11 studies included 3751 subjects. Of these, 2700 were managed expectantly, and 1051 underwent labor induction. We calculated an estimate of the odds ratio (OR) with 95% confidence intervals (CIs) for dichotomous outcomes, using random- and fixed-effects models for outcomes. Summary statistics for the nine observational studies showed that, compared with those whose labor was induced, women who experienced spontaneous onset of labor had a lower incidence of cesarean delivery (OR 0.39, 95% CI 0.30, 0.50) and higher rates of spontaneous vaginal delivery (OR 2.07, 95% CI 1.34, 3,19); however, significant differences in these outcomes were not noted when the two randomized trials were assessed. No differences were noted in rates of operative vaginal deliveries, incidence of shoulder dystocia, or abnormal Apgar scores in the analyses of the observational or randomized studies.
CONCLUSION: Based on data from observational studies, labor induction for suspected fetal macrosomia results in an increased cesarean delivery rate without improving perinatal outcomes. Although their statistical power is limited, randomized clinical trials have not confirmed these findings.
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.
