BACKGROUND: Very little is known about the prevalence and risk factors of postpartum depression among women with vaginal births without major pregnancy complications. OBJECTIVE: This study aimed to assess the prevalence of postpartum depression and identify its characteristics 2 months after singleton vaginal delivery at or near term. STUDY DESIGN: This was an ancillary cohort study of the TRanexamic Acid for Preventing Postpartum Hemorrhage After Vaginal Delivery randomized controlled trial, which was conducted in 15 French hospitals in 2015-2016 and enrolled women with singleton vaginal deliveries after 35 weeks of gestation. After randomization, the characteristics of labor, delivery, and the immediate postpartum experience, including the experience of childbirth, were prospectively collected. Medical records provided women's other characteristics, particularly any psychiatric history. Of note, 2 months after childbirth, provisional postpartum depression diagnosis was defined as a score of ≥13 on the Edinburgh Postnatal Depression Scale, a validated self-administered questionnaire. The corrected prevalence of postpartum depression was calculated with the inverse probability weighting method to take nonrespondents into account. Associations between potential risk factors and postpartum depression were analyzed by multivariate logistic regression. Moreover, an Edinburgh Postnatal Depression Scale cutoff value of ≥11 was selected to perform a sensitivity analysis. RESULTS: The questionnaire was returned by 2811 of 3891 women (72.2% response rate). The prevalence rates of the provisional diagnosis were 9.9% (95% confidence interval, 8.6%-11.3%) defined by an Edinburgh Postnatal Depression Scale score of ≥13 and 15.5% (95% confidence interval, 14.0%-17.1%) with a cutoff value of ≥11. The characteristics associated with higher risks of postpartum depression in multivariate analysis were mostly related to prepregnancy characteristics, specifically age of