(Am J Obstet Gynecol. 2017;217(1):63.e1–63.e10)
Cesarean delivery rates are on the rise in the United States, in part because of the increased use of cesarean delivery rather than forceps and vacuum deliveries for fetal distress and arrest disorders in the second stage of labor. However, cesarean delivery in the second stage of labor can be risky due to the difficulty of delivering a deeply impacted fetal head. Cohort studies have shown increased risk of extensions of the uterine incision, bladder injury, and postpartum hemorrhage in such deliveries. Surgical trauma to the cervix from other procedures has been demonstrated to significantly increase the risk of subsequent premature delivery. For these reasons, the authors hypothesized that second-stage cesarean deliveries may increase the rate of subsequent spontaneous preterm delivery.