BackgroundChildbirth has been linked to postpartum impairment. However, controversy exists regarding the onset and prevalence of post-traumatic stress disorder (PTSD) after childbirth, with seminal studies being limited by methodological issues. This longitudinal prospective study examined the prevalence of PTSD following childbirth in a large sample while controlling for pre-existing PTSD and affective symptomatology.MethodPregnant women in their third trimester were recruited over a 12-month period and interviewed to identify PTSD and anxiety and depressive symptoms during the last trimester of pregnancy, 4–6 weeks postpartum, 12 weeks postpartum and 24 weeks postpartum.ResultsOf the 1067 women approached, 933 were recruited into the study. In total, 866 (93%) were retained to 4–6 weeks, 826 (89%) were retained to 12 weeks and 776 (83%) were retained to 24 weeks. Results indicated that, uncontrolled, 3.6% of women met PTSD criteria at 4–6 weeks postpartum, 6.3% at 12 weeks postpartum and 5.8% at 24 weeks postpartum. When controlling for PTSD and partial PTSD due to previous traumatic events as well as clinically significant anxiety and depression during pregnancy, PTSD rates were less at 1.2% at 4–6 weeks, 3.1% at 12 weeks and 3.1% at 24 weeks postpartum.ConclusionsThis is the first study to demonstrate the occurrence of full criteria PTSD resulting from childbirth after controlling for pre-existing PTSD and partial PTSD and clinically significant depression and anxiety in pregnancy. The findings indicate that PTSD can result from a traumatic birth experience, though this is not the normative response.