Small PDAs, and those which were successfully treated in childhood without the development of other symptoms, pose no significant problems for pregnancy. There is the risk of heart failure in women with substantial left to right shunts and the enlargement of the left heart. These patients will require careful monitoring during pregnancy and immediately thereafter.
Pregnancy can be dangerous for patients with large untreated PDAs, with high mortality rates for both mothers and their unborn children.
Anyone with congenital heart disease, repaired or non-repaired, should consult with their cardiologist prior to becoming pregnant to review the risks.