Intravenous nitroglycerin resulting in uterine relaxation has been standardly utilized for various obstetrics conditions, e.g. breech extraction of second twin in vaginal deliveries, uterine relaxation after tachysystole in labor, prior to external cephalic version, and during difficult fetal extraction during cesarean delivery for arrest of descent in labor. Currently the use of nitroglycerin is at equipoise in obstetrics for difficult cesarean delivery after second stage arrest in labor. The clinical trial will randomize women who undergo cesarean delivery for second stage arrest in labor to receive IV nitroglycerin vs saline at the time of hysterotomy. The primary outcomes will be maternal: uterine extension, blood loss, total fetal extraction time, surgical time; neonatal: cord gases at delivery, apgar scores, admission to neonatal intensive care unit.
