Higher Rates of Operative Delivery and Maternal and Neonatal Complications in Persistent Occiput Posterior Position with a Large Head Circumference: A Retrospective Cohort Study

Introduction: We investigated whether large head circumference (HC) combined with persistent occiput posterior (OP) position is associated with higher rates of operative delivery and obstetric and neonatal complications than OP deliveries without large HC or in occiput anterior (OA) position. Materials and Methods: Term singleton deliveries in our centers from January 2010 to December 2014, delivered in cephalic OA (n = 41,038) or OP position (n = 1,740), were assessed. We compared delivery modes, maternal and neonatal complications in OA versus OP deliveries, and HC ≥90th centile versus HC <90th centile in persistent OP position. Results: Persistent OP position combined with HC ≥90th centile was associated with higher rates of vacuum extraction and unplanned cesarean delivery than HC <90th centile in OP position (20.1 vs. 17.2%, OR 1.53 [95% CI 0.99-2.36], and 23.4 vs. 9.2%, OR 3.326 [95% CI 2.17-5.11], respectively). Rates of prolonged second stage of labor and neonatal intensive care unit admission were also increased compared to those in either OA position with HC ≥90th centile or OP position with HC <90th centile. Discussion: Large HC combined with OP position is associated with higher rates of operative delivery and prolonged second stage of labor compared to OP delivery with HC <90th centile. HC might be included with other measures to assess women in labor, as it is associated with fetal outcomes in OP deliveries.