Maternal and neonatal implications of congenital complete heart block in the fetus.

The detection of congenital complete heart block (CCHB) in a fetus should alert the obstetrician that the welfare of both the mother and the newborn infant may be in jeopardy. An awareness of this uncommon cause of fetal bradycardia and judicious intrapartum monitoring can avert hasty and unnecessary cesarean section for suspected fetal asphyxia. Neonatal consequences may range from no effect to life-threatening congestive heart failure. The apparently healthy mothers of these infants may be at increased risk for the subsequent development of collagen vascular disease. Three recent case reports demonstrate the spectrum of neonatal and maternal disease that may accompany CCHB. The significance of abnormal serology suggesting a propensity for collagen vascular disease in an otherwise healthy parturient is discussed, and a program for follow-up is proposed.