Induction of labor versus expectant management for post-date pregnancy: is there sufficient evidence for a change in clinical practice?

OBJECTIVES To compare perinatal and maternal outcomes between elective induction of labor versus expectant management of pregnancies at 41 weeks and beyond. DESIGN Systematic review and meta-analysis. METHODS We searched PubMed, CINAHL, Cochrane Database of Systematic Reviews (CDSR), Database of Abstracts of Reviews of Effectiveness (DARE) and PsycINFO (1980 to November, 2007). Inclusion criteria were systematic reviews and randomized controlled trials comparing elective induction of labor versus expectant management of pregnancies at 41 weeks and beyond. Three or more reviewers independently read and evaluated all selected studies. Data were extracted and analyzed using Review Manager Software. MAIN OUTCOME MEASURES Perinatal mortality. RESULTS Thirteen trials fulfilled the inclusion criteria for the meta-analysis. Elective induction of labor was not associated with lower risk of perinatal mortality compared to expectant management (relative risks (RR): 0.33; 95% confidence intervals (CI): 0.10-1.09). Elective induction was associated with a significantly lower rate of meconium aspiration syndrome (RR: 0.43; 95% CI: 0.23-0.79). More women randomized to expectant management were delivered by cesarean section (RR: 0.87; 95% CI: 0.80-0.96). CONCLUSIONS The meta-analysis illustrated a problem with rare outcomes such as perinatal mortality. No individual study with adequate sample size has been published, nor would a meta-analysis based on the current literature be sufficient. The optimal management of pregnancies at 41 weeks and beyond is thus unknown.