Pregnancy outcomes in women with complex CHD, mWHO III and IV

Background

Pregnancy imposes haemodynamic and prothrombotic stress, and women with complex congenital heart disease (CHD) classified as modified WHO (mWHO) class III or IV face increased risks of adverse obstetric and neonatal outcomes, requires coordinated multidisciplinary management. However available data in the patients remain limited.

Methods

We performed a retrospective descriptive study of consecutive pregnancies in women with mWHO III-IV CHD followed by a multidisciplinary pregnancy–heart team between 2020 and 2024. Baseline characteristics, maternal and obstetric outcomes were systematically collected. Haemodynamic status during pregnancy was assessed by NYHA functional class and serial NT-proBNP measurements.

Results

12 women and 13 pregnancies were included (39.5% mWHO IV), with 11 completed deliveries. Two pregnancies were electively interrupted, one due to patient decision and another after counselling, owing to failing Fontan circulation. The mean maternal age was 29.8±5.2 years; 62% had prior corrective and 46% palliative surgery. Diagnoses included systemic right ventricle after atrial switch for D-TGA (42%), Fontan circulation (17%), repaired TOF with significant residual lesions (17%), unrepaired complex cyanotic CHD (8.3%), and atrioventricular septal defects (AVSD) with AV valve regurgitation or mechanical prosthesis (25%). Significant valvular disease was present in 62%, and previous arrhythmia in 31%. At baseline, most patients were NYHA class I–II and median NTproBNP was 126 (65-377) pg/mL with minor changes during pregnancy.

Among the completed pregnancies, the median gestational age at delivery was 39 (38–40) weeks. Caesarean section was performed in 45%. Maternal complications included decompensated heart failure in 2 patients (D-TGA with pulmonary baffle stenosis and failing Fontan) and postpartum cardiovascular hospitalisation in a patient with AVSD and mechanical left AV valve stenosis by mismatch. Obstetric complications occurred in 36%, 2 patients with AVSD, one with severe left AV valve regurgitation and another with left mechanical prosthetic mismatch, had postpartum haemorrhage, and 1 patient with D-TGA and pulmonary baffle stenosis had a hypertensive disorder. Neonatal outcomes were favourable; one neonate, born to a mother with unrepaired complex cyanotic CHD, had low birth weight and congenital heart disease and died at two months old. No maternal deaths occurred.

Conclusion

This cohort of women with mWHO III–IV CHD managed within a specialised multidisciplinary programme, pregnancy was feasible with acceptable maternal and neonatal outcomes, although cardiac and obstetric complications remained common. These findings highlight the importance of meticulous pre-pregnancy counselling, individualised risk stratification, and close surveillance throughout gestation in high-risk congenital heart disease.For image description, please refer to the figure legend and surrounding text.For image description, please refer to the figure legend and surrounding text.