Maternal and neonatal complications in women with congenital heart disease: a nationwide analysis

AIMS The aim of this study was to provide population-based data on maternal and neonatal complications and outcome in the pregnancies of women with congenital heart disease (CHD). METHODS AND RESULTS Based on administrative data from one of the largest German Health Insurance Companies (BARMER GEK, ∼9 million members representative for Germany), all pregnancies in women with CHD between 2005 and 2018 were analysed. In addition, an age-matched non-CHD control group was included for comparison and the association between adult CHD (ACHD) and maternal or neonatal outcomes investigated. Overall, 7512 pregnancies occurred in 4015 women with CHD. The matched non-CHD control group included 6502 women with 11 225 pregnancies. Caesarean deliveries were more common in CHD patients (40.5% vs. 31.5% in the control group; P < 0.001). There was no excess mortality. Although the maternal complication rate was low in absolute terms, women with CHD had a significantly higher rate of stroke, heart failure and cardiac arrhythmias during pregnancy (P < 0.001 for all). Neonatal mortality was low but also significantly higher in the ACHD group (0.83% vs. 0.22%; P = 0.001) and neonates to CHD mothers had low/extremely low birth weight or extreme immaturity (<0.001) or required resuscitation and mechanical ventilation more often compared to non-CHD offspring (P < 0.001 for both). On multivariate logistic regression maternal defect complexity, arterial hypertension, heart failure, prior fertility treatment, and anticoagulation with vitamin K antagonists emerged as significant predictors of adverse neonatal outcome (P < 0.05 for all). Recurrence of CHD was 6.1 times higher in infants to ACHD mothers compared to controls (P < 0.0001). CONCLUSIONS This population-based study illustrates a reassuringly low maternal mortality rate in a highly developed healthcare system. Nevertheless, maternal morbidity and neonatal morbidity/mortality were significantly increased in women with ACHD and their offspring compared to non-ACHD controls highlighting the need of specialized care and pre-pregnancy counselling.