Pregnancy outcomes in women with transposition of the great arteries and arterial switch operation

There is a growing population of young women of child-bearing age with complete transposition of the great arteries (TGA) who have had an arterial switch operation (ASO). Pregnancy imposes a hemodynamic stress on the heart and, therefore, adverse cardiac events can occur during this period; however, pregnancy outcomes in this population have not been well studied. We sought to describe cardiac outcomes during pregnancy in women with TGA who had undergone an ASO in childhood. Women were identified from 2 large tertiary care hospitals. A retrospective chart review was performed to determine the prevalence of adverse maternal cardiac events during pregnancy. Overall, 74 women of child-bearing age were identified, 9 of whom had 17 pregnancies. There were 4 miscarriages. Six women (67%) had clinically important valve (n = 5) and ventricular (n = 1) lesions before the index pregnancy. Two women developed cardiac complications during pregnancy; 1 woman with impaired left ventricular systolic function had nonsustained ventricular tachycardia and 1 woman with a mechanical systemic atrioventricular valve developed postpartum valve thrombosis. There were no maternal deaths. In conclusion, young women with TGA from this early cohort repaired with ASO are reaching child-bearing age. A significant proportion have residua and/or sequelae that can confer risk for adverse cardiac events in pregnancy. Co-ordinated care between a congenital heart disease specialist and a high-risk obstetrician should be implemented.