Risk factors

In most cases, the cause of a congenital heart defect, such as tricuspid atresia, is unknown. However, several things might increase the risk of a baby being born with a congenital heart defect, including:

• A mother who had German measles (rubella) or another viral illness during early pregnancy
• A parent who has a congenital heart defect
• Drinking alcohol during pregnancy
• Smoking before or during pregnancy
• A mother who has poorly controlled diabetes
• Use of some types of medications during pregnancy, such as the acne drug isotretinoin (Claravis, Amnesteem, others), some anti-seizure medications and some bipolar disorder medications
• The baby is born with Down syndrome, a genetic condition that results from an extra 21st chromosome