Long‐Term Cardiovascular Health After Pregnancy in Danish Women With Congenital Heart Disease. A Register‐Based Cohort Study Between 1993 and 2016

BACKGROUND: Little is known about the impact of pregnancy on long‐term cardiovascular health in individuals with congenital heart disease (CHD). We aimed to determine if giving birth in patients with CHD is associated with higher risk of long‐term cardiovascular morbidity. METHODS AND RESULTS: We studied a cohort of 1262 individuals with CHD giving birth (live or still) from 1993 to 2015 using Danish nationwide registers. We randomly sampled a comparison cohort matched on age of women with CHD who had not given birth at the time. We balanced the 2 cohorts on baseline demographic (eg, education) and clinical variables (eg, CHD severity) using inverse probability of treatment weighting. Individuals were followed for critical (eg, heart failure), other cardiovascular morbidity (eg, arrhythmia), and cardiac surgery/interventions after pregnancy. Individuals were followed for median 6.0 years (interquartile range 3.2–9.2). Among individuals giving birth the incidence rate per 1000 person‐years was 1.6, 10.0, and 6.0 for critical and other cardiovascular morbidity and cardiac surgery, respectively. There was no overall difference in risk of neither critical and other cardiovascular morbidity nor cardiac surgery among individuals who gave birth and individuals who did not; adjusted hazard ratios (aHR) were 0.74 (95% CI, 0.37–1.48), 0.88 (95% CI, 0.65–1.19), and 0.78 (95% C,I 0.54–1.12), respectively. However, individuals with obstetric complications had a higher long‐term risk of other cardiovascular morbidity (aHR, 1.85; 95% CI, 1.07–3.20). CONCLUSIONS: Giving birth seemed not to be associated with a higher risk of long‐term cardiovascular morbidity among women with CHD. However, individuals having obstetric complications had a higher risk of other cardiovascular morbidity in the long term.