Successful pregnancies in two women with hypoplastic left heart syndrome

Hypoplastic left heart syndrome (HLHS) is a relatively common complex congenital heart defect. Prior to development of staged reconstruction (i.e., Norwood procedure), HLHS was almost universally fatal within months of birth. Early survivors of the Norwood procedure are now reaching reproductive age. We report successful pregnancies in two such women.

The first patient was a 20-year-old woman transferred from a community hospital at 33 3/7 weeks gestation because of preterm labor, suspected preeclampsia, and mild chronic hypoxemia. She had normal systemic ventricular shortening without significant valvar regurgitation but severe neoaortic dilatation. A fetal ultrasound demonstrated intrauterine growth restriction. An urgent Cesarean section was performed at 33 6/7 weeks gestation, given breech position and intractable preterm labor. The second patient, a 23-year-old woman followed at this institution through pregnancy, presented with preterm labor at 36 weeks gestation. Her systemic ventricular shortening was normal, with mild tricuspid regurgitation but without neoaortic dilation or regurgitation. She developed active labor at 36 3/6 weeks, and had a spontaneous vaginal delivery of a small for gestational age infant. Both women tolerated labor and childbirth without complication. Neither infant had evidence of structural heart disease on fetal echocardiography or physical examination.

These cases, the first reported successful pregnancies in mothers with HLHS, highlight the challenges of pregnancy among women with complex congenital heart disease in general and raise several considerations specific to HLHS.