Around 140 million births occur worldwide annually. For some women, childbirth is traumatic and can lead to childbirth-related post-traumatic stress disorder (CB-PTSD), with adverse consequences for both women and their families. However, international evidence remains limited.

To estimate the international prevalence of traumatic birth and CB-PTSD.

The International Survey of Childbirth-Related Trauma (INTERSECT) is a cross-sectional survey conducted in 31 countries. Women were eligible if they were 6–12 weeks postpartum, legally adults and provided informed consent. Recruitment was through routine maternity services and data were collected from April 2021 to January 2024. Outcomes were assessed using the City Birth Trauma Scale. Traumatic birth was coded using DSM-5 criteria for a traumatic stressor, and CB-PTSD classified when all PTSD criteria were met. Dissociative subtype and differential diagnoses were also assessed.

A total of 11 302 women from 31 countries took part. Most participants were married, aged 30–34 years, with average household income and higher education, and 9.7% identified as being from ethnic or racial minority groups. The prevalence of traumatic birth and CB-PTSD varied across countries: traumatic birth ranged from 7 to 69% (mean 23.3, 95% CI 22.4–24.0), and CB-PTSD ranged from 1 to 36% (mean 6.7, 95% CI 3.7–9.7). CB-PTSD subtypes also varied: the dissociative subtype ranged from 1 to 24% (mean 3.8, 95% CI 2.1–5.4) and acute CB-PTSD from 0 to 7% (mean 1.3, 95% CI 0.7–1.9). Removal of participants with potential differential diagnoses did not affect prevalence rates in most countries. Many participants reported distress and impairment from symptoms, even when they did not meet CB-PTSD diagnostic criteria.

Results show that a notable proportion of women experience traumatic birth and CB-PTSD. The wide variation in prevalence suggests that cultural and healthcare factors unique to each country are important. Results emphasise the importance of routine trauma-informed assessment and culturally informed support in perinatal mental healthcare.