The study examined the effect of synthetic oxytocin administered during labor in 1,296 women. Overall, 63.3% of participants received oxytocin. In women with vaginal delivery, oxytocin exposure was associated with lower exclusive breastfeeding at two months postpartum (58.2% versus 70.3%), but did not affect mental health outcomes. In women with unscheduled cesarean delivery, oxytocin exposure was associated with higher postpartum depressive symptoms immediately after delivery, acute childbirth-related stress, and posttraumatic stress symptoms at two months. The research suggests that oxytocin during labor may be associated with increased maternal vulnerability in certain delivery contexts.