Trisomy 18 and complex congenital heart disease: seeking the threshold benefit.

A prenatal diagnosis of ductal-dependent, complex congenital heart disease was made in a fetus with trisomy 18. The parents requested that the genetic diagnosis be excluded from all medical and surgical decision-making and that all life-prolonging therapies be made available to their infant. There was conflict among the medical team about what threshold of neonatal benefit could outweigh maternal and neonatal treatment burdens. A prenatal ethics consultation was requested.