Prenatal diagnosis of nonsyndromic congenital heart defects

Congenital heart defects (CHDs) occur in nearly 1% of live births. We sought to assess factors associated with prenatal CHD diagnosis in the National Birth Defects Prevention Study (NBDPS).

We analyzed data from mothers with CHD-affected pregnancies from 1998 to 2005. Prenatal CHD diagnosis was defined as affirmative responses to questions about abnormal prenatal ultrasounds and fetal echocardiography obtained during a structured telephone interview.

Fifteen percent (1097/7299) of women with CHD-affected pregnancies (excluding recognized syndromes and single-gene disorders) reported receiving a prenatal CHD diagnosis. Prenatal CHD diagnosis was positively associated with advanced maternal age, family history of CHD, type 1 or type 2 diabetes, twin or higher-order gestation, CHD complexity, and presence of extracardiac defects. Prenatal CHD diagnosis was inversely associated with maternal Hispanic race/ethnicity, prepregnancy overweight or obesity, and preexisting hypertension. Prenatal CHD diagnosis varied by time to NBDPS interview and NBDPS study site.

Further work is warranted to identify reasons for the observed variability in maternal reports of prenatal CHD diagnosis and the extent to which differences in health literacy or health system factors such as access to specialized prenatal care and fetal echocardiography may account for such variability.