title: The Association between Early Artificial Amniotomy and Chorioamnionitis in Nulliparous Induction of Labor.
abstract: Objectives. To investigate whether early artificial amniotomy (AROM) <4 cm in nulliparous women admitted for induction of labor was associated with an increased rate of chorioamnionitis and cesarean section or a decreased time to vaginal delivery. Study Design. A retrospective cohort study was performed on nulliparous women with a term, singleton gestation and intact membranes who presented for induction of labor (January 2008 to December 2011). Chorioamnionitis was defined using ICD9 codes. Results. 1,567 women were enrolled; 25.4% underwent early AROM. Overall, the prevalence of chorioamnionitis was 12.4%, the rate of cesarean section was 32.2%, and the time from 4 cm cervical dilation to vaginal delivery was 413 min. Compared to women without AROM < 4 cm, early AROM did not affect overall chorioamnionitis rates (10.2 versus 13.2%, P = 0.12) but was associated with an increased cesarean section rate (40.2 versus 29.5%, P < 0.001). However, among those who delivered vaginally, AROM < 4 cm decreased the rate of chorioamnionitis (8.4 versus 14.6%, P = 0.01), which persisted when controlling for potential confounders (OR 0.55, 95% CI 0.33-0.92), and decreased the time from 4 cm dilation to vaginal delivery (329 versus 472 min, P < 0.001). Conclusions. Our findings do not suggest that early AROM is associated with an increased rate of clinical chorioamnionitis.
authors.affiliation: Maternal and Child Health Research Program, Department of Obstetrics and Gynecology, Center for Research on Reproduction and Women's Health Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
authors.forename: Laura G
authors.initials: LG
authors.lastname: Cooney
authors.affiliation: Maternal and Child Health Research Program, Department of Obstetrics and Gynecology, Center for Research on Reproduction and Women's Health Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Hospital of the University of Pennsylvania, 3400 Spruce Street, 585 Dulles Building, Philadelphia, PA 19104, USA.
authors.forename: Jamie A
authors.initials: JA
authors.lastname: Bastek