title: Prelabor rupture of the membranes at term: when to induce labor?
abstract: OBJECTIVE
  To determine the significant predictors of clinical chorioamionitis and neonatal infection in patients with prelabor rupture of the membranes at term, and to apply this information to determination of optimal timing of labor induction.
  
  
  METHODS
  A retrospective case control series of women at > or =37 weeks' with prelabor rupture of the membranes. The study group consisted of women with evidence of maternal or neonatal infection. Controls had no evidence of infection. Three types of management were compared. (1) Immediate induction of labor, (2) expectant management up to 24 h followed by induction of labor if still necessary, or (3) expectant management for over 24 h. Univariate and multivariate analyses were performed by stepwise logistic regression (SPSS software package). The size of the study and the control groups was calculated for a 90% power with two sided P value of 0.05 in order to demonstrate an odds ratio of 2 for expectant management (two groups: early and late) versus immediate induction of labor (132 and 279 women in the study and the control groups, respectively).
  
  
  RESULTS
  The rate of expectant management for over 24 h versus expectant management until 24 h followed by induction of labor when still necessary, was higher among cases than among controls ( OR = 1.84; P < 0.017; 95% CI, 1.127-3.003). Conversely, the rate of immediate induction of labor versus expectant management until 24 h followed by induction of labor when still necessary, was also higher among cases ( OR = 2.66; P < 0.001; 95% CI, 0.222-0.644).
  
  
  CONCLUSIONS
  In women with prelabor rupture of the membranes at term, the best approach is to induce labor if spontaneous labor has not begun after 24 h.
authors.affiliation: Department of Obstetrics and Gynecology, Hadassah Medical Center, The Hebrew University School of Medicine, P.O. Box 12000, Jerusalem 91120, Israel. ezray@cc.huji.ac.il
authors.forename: Yossef
authors.initials: Y
authors.lastname: Ezra
authors.forename: Rachel
authors.initials: R
authors.lastname: Michaelson-Cohen
authors.forename: Yoram
authors.initials: Y
authors.lastname: Abramov
authors.forename: Nathan
authors.initials: N
authors.lastname: Rojansky
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D016022:Case-Control Studies; D002821:Chorioamnionitis / Q000453:epidemiology; D005260:Female; D005322:Premature Rupture of Fetal Membranes / Q000150:complications*; D006801:Humans; D007231:Infant, Newborn; D007239:Infections / Q000453:epidemiology; D007751:Labor, Induced; D016015:Logistic Models; D011247:Pregnancy; D012189:Retrospective Studies; D013997:Time Factors