SEVERE PREECLAMPSIA REMOTE FROM TERM - LABOR INDUCTION OR ELECTIVE CESAREAN DELIVERY

OBJECTIVES: The study's objectives were as follows: (1) to determine t he rate of vaginal delivery after labor induction in severe preeclamps ia remote from term and (2) to determine potential predictors of succe ss. STUDY DESIGN: Retrospective chart review was conducted on live-bor n singleton pregnancies complicated by severe preeclampsia and deliver ed at 24 to 34 weeks' gestation from January 1, 1992, to December 31, 1996. Exclusion criteria included eclampsia, presence of labor or spon taneous rupture of membranes on admission, and complication of pregnan cy by an ultrasonographically detected fetal congenital anomaly. Patie nts were divided into 3 groups: elective cesarean delivery without lab or, cesarean delivery after labor induction, and vaginal delivery afte r labor induction. Statistical analyses included multiple logistic reg ression, the Student t test, the chi(2) test, and the Mann-Whitney tes t. P less than or equal to .05 was considered significant. RESULTS: A total of 306 charts were reviewed. Among these, 161 patients (52.6%) u nderwent elective cesarean delivery without labor; the 2 most common i ndications were unfavorable cervix (33.5%) and malpresentation (22.4%) . The remaining 145 patients (47.4%) underwent labor induction with a 48.3% rate of vaginal delivery after induction, ranging from 31.6% at less than or equal to 28 weeks' gestation to 62.5% at >32 weeks' gesta tion. The most common indication for cesarean delivery after induction , in 50.7% of the cases, was nonreassuring fetal heart rate. The media n Bishop score was significantly higher (3 vs 2, P = .004) and the tot al hospital stay was significantly shorter in the vaginal delivery aft er induction group than in the cesarean delivery after induction group . However, there were no significant differences between the 2 groups in use of cervical ripening agents, gestational age at delivery, birth weight, 5-minute Apgar score, or postpartum endometritis. After exclu sion of cesarean deliveries performed for malpresentation, there was n o statistically significant difference in classic incision rates betwe en the elective cesarean delivery without labor and cesarean delivery after induction groups (13.6% vs 6.8%; P = .137). According to logisti c regression analysis, only the Bishop score was significantly associa ted with a successful induction (odds ratio 1.38, 95% confidence inter val 1.11-1.71). Gestational age reached marginal significance (odds ra tio 1.30, 95% confidence interval 0.89-1.89). CONCLUSIONS: (1) Labor i nduction should be considered a reasonable option for patients with se vere preeclampsia at less than or equal to 34 weeks' gestation because 48% of patients given the chance were successfully delivered vaginall y. (2) The Bishop score on admission is the best predictor of success, although the chance of successful labor induction increases with adva ncing gestational age.