Congenital heart defects, such as Ebstein's anomaly, happen early in the development of a baby's heart. It's uncertain what risk factors might cause the defect. Genetic and environmental factors are both thought to play a role. People with a family history of heart defects may be more likely to have Ebstein's anomaly. A mother's exposure to certain medications, such as lithium or benzodiazepines, has been associated with Ebstein's anomaly in the child.

Jan. 21, 2016