Recent research has shed light on the impact of endometriosis on complications during pregnancy, but very few studies address the influence of deep endometriosis (DE) on delivery and peripartum parameters. For this reason, an international birth register for DE was established to aid in counseling affected women on delivery mode and individual risks.

The BiRDeE study (Birth Register for Deep Endometriosis) is an international noninterventional multicenter study based on a patient register of women with singleton live births after diagnosis of DE (both operated on and non-operated). This first extracted data was analysed using descriptive statistics and logistic regression.

At the time point of data extraction (January 2023), 10 study centres created 209 records of which 165 were closed and suitable for analysis. Cesarean section was performed in 49.1% of patients with a high rate of elective CS due to known deep endometriosis. The median gestational age at delivery was 40 weeks of pregnancy (IQR 39–41) with a preterm delivery rate of 10.9%. In four cases, Apgar scores at 5 min were less than seven; there were no cases with an umbilical artery pH < 7.00 (lowest NapH value was 7.08). No bladder or bowel injuries (beside OASIS) were reported so far.

Deep endometriosis per se is not a contraindication for vaginal delivery. Based on the currently available data, the choice of delivery method should be made together with the patient after adequate information about benefits and possible complications. Neonatal outcomes are encouraging.