Cardiovascular diseases remains the leading cause of maternal mortality within 42 days postpartum in France, representing a major public health issue. Advances in medical and surgical care have enabled an increasing number of patients with adult congenital heart disease (ACHD) to achieve pregnancy. However, contemporary data on maternal and neonatal outcomes in this population remain limited.

To describe cardiovascular, obstetric and neonatal adverse outcomes in pregnant patients with ACHD.

We conducted a multicenter, retrospective cohort study in Marseille, France, including all consecutive pregnancies in patients with ACHD between 2015 and 2024. Cardiovascular, obstetric and neonatal outcomes were assessed from pregnancy through the peripartum period and up to one year postpartum.

A total of 129 pregnancies in 90 patients with ACHD were included. The most common ACHDs were tetralogy of Fallot (18.6%), ventricular septal defect (17.8%), and aortic coarctation (10.9%). Although 44.2 % of pregnancies were classified as modified WHO 2.0 > II, no maternal deaths were observed. Only 4.7% of pregnancies benefited from multidisciplinary preconception counseling. Cardiovascular events occurred in 17.8% of pregnancies, with heart failure and arrhythmias being the leading events (8.5% each). Cardiovascular risk-guided caesarean delivery was performed in 16.3% of cases, including 9.3% elective procedures. Adverse neonatal outcomes were frequent, including intrauterine growth restriction (15.5%), preterm delivery (17.8%), and small for gestational age at birth (34.9%).

Pregnant patients with ACHD experience substantial maternal, and neonatal morbidity. These findings underscore the need of early cardiovascular risk stratification, multidisciplinary preconception counseling, and coordinated care to optimize outcomes.