Introduction: The normal hemodynamic changes of pregnancy can trigger cardiac dysfunction in women with congenital heart defects (CHD), leading to an increased risk of cardiac events. Further, utero-placental flow is impaired in women with CHD which can result in higher risk of adverse offspring outcomes.
Hypothesis: Severity of maternal CHD is associated with adverse maternal cardiovascular events and offspring events by severity of CHD in 1074 pregnancies that resulted in a live birth in Colorado between 2011-13.
Methods: Using data from the Colorado CHD Surveillance System in Adolescents and Adults, 926 pregnant women with CHD were identified that resulted in 1074 live births between 2011-2013. Maternal CHD type was dichotomized as severe (n=149) and moderate (total n=882). The risk of adverse maternal cardiac and offspring events were calculated out of the total number of pregnancies in each severity category.
Results: Primary maternal cardiac events including cardiovascular mortality, arrhythmia, heart failure, thromboembolic events (pulmonary embolism, valve thrombosis or deep venous thrombosis), vascular events (stroke, myocardial infarction or dissection) and endocarditis occurred in 15% and 7% of women with severe and moderate CHD, respectively. Premature birth (delivery <37 weeks) and/or low birth weight (<2,500 grams) occurred in >18% of the women with severe CHD and 17% of women with moderate CHD. The risk of offspring congenital anomalies among women with severe CHD was extremely high for circulatory/respiratory, musculoskeletal/integumentary, cyanotic congenital heart disease and Down syndrome. The risk of infant congenital anomalies was lower for women with moderate CHD, with the most common being circulatory/respiratory, urogenital, Down syndrome and cyanotic congenital heart disease.
Conclusions: Population-level surveillance system of CHD in Colorado provides novel assessment of the substantial risk of maternal and neonatal cardiac events associated with pregnancy in women with CHD.