Congenital Uterine Malformations and Pregnancy Outcomes: A Retrospective Observational Study to Inform Reproductive Counseling.

Introduction: Congenital uterine malformations are often associated with uncertainty regarding pregnancy outcomes and reproductive counseling. Data on obstetric outcomes stratified by detailed anatomical classification remain limited. Materials and Methods: In this retrospective observational case series, pregnancy and delivery outcomes were analyzed in women with congenital uterine malformations classified according to the VCUAM system. The cohort included 95 deliveries in women with septate (U1, n = 49), bicornuate (U2, n = 40), or unicornuate (U4a, n = 6) uterus managed at a tertiary perinatal referral center. Pregnancy complications, mode of delivery, peripartum complications, and neonatal outcomes were assessed descriptively. Results: Overall, 68.8% of pregnancies (64/93; 95% CI 58.7-77.4) occurred without documented complications. Cervical insufficiency was observed in 12.9% (12/93; 95% CI 7.6-21.2) and preterm labor in 7.5% (7/93; 95% CI 3.7-14.7). Severe obstetric complications were rare. Cesarean delivery was common. However, vaginal delivery was achieved in all uterine subtypes. Neonatal condition at birth was generally reassuring across groups. Conclusion: In this cohort of deliveries among women with congenital uterine malformations reaching viable pregnancy, most pregnancies progressed without documented major complications and neonatal outcomes were generally favorable. These findings support individualized reproductive counseling and structured obstetric surveillance while avoiding assumptions based solely on uterine anatomy.