Background: Little is known about the relationship between women's birthing experiences and the development of trauma symptoms. This study aimed to determine the incidence of acute trauma symptoms and posttraumatic stress disorder (PTSD) in women as a result of their labor and delivery experiences, and identify factors that contributed to the women's psychological distress. Method: Using a prospective, longitudinal design, women in their last trimester of pregnancy were recruited from four public hospital antenatal clinics. Four to six weeks postpartum, telephone interviews were conducted with participants (n = 499) and explored the medical and midwifery management of the birth, perceptions of intrapartum care, and the presence of trauma symptoms. Results: One in three women (33%) identified a traumatic birthing event and reported the presence of at least three trauma symptoms. Twenty-eight women (5.6%) met DSM-IV criteria for acute posttraumatic stress disorder. Antenatal variables were not found to contribute to the development of acute or chronic trauma symptoms. The level of obstetric intervention experienced during childbirth (beta = .351, p <.0001) and the perception of inadequate intrapartum care (beta = .319, p <.0001) during labor were consistently associated with the development of acute trauma symptoms. Conclusions: Posttraumatic stress disorder following childbirth is an under-recognized phenomenon. Women who experienced both a high level of obstetric intervention and were dissatisfied with their intrapartum care were more likely to develop trauma symptoms than women who received a high level of obstetric intervention or women who perceived their care to be inadequate. Such findings should prompt a serious review of intrusive obstetric intervention during labor and delivery, and the psychological care provided to birthing women.