Perinatal management of congenital complete heart block.

Background: The perinatal management of congenital complete heart block (CCHB) remains controversial. The purpose of this study was to present a therapeutic modality for CCHB.

Methods: We collected retrospective cases of all pregnant women admitted to our hospital between January 1992 and June 1999 whose babies developed CCHB antenatally. After a series of examinations, maternal, fetal and neonatal data were analyzed.

Results: Nine fetuses from six mothers (cases 1-6) in nine different pregnancies were studied. In case 1, both consecutive fetuses had CCHB and in case 2, all three consecutive fetuses had CCHB. The other mothers (cases 3-6) had only one fetus each with CCHB. Of the seven fetuses with isolated CCHB, four underwent observation only due to late-onset, or nonimmunologic CCHB, two received dexamethasone and/or intravenous immunoglobulin therapy because of the presence of hydropic signs, and one received dexamethasone at 23 weeks' gestation due to early-onset CCHB. Shortening fractions of the right ventricle had good compensation in four fetuses, without any treatment, and improving compensation in two of three fetuses receiving dexamethasone therapy. All seven fetuses were delivered smoothly and pacemakers were implanted shortly after birth. Two other fetuses had a poor outcome due to associated ventricular septal defect or hemoglobin Bart's disease. Furthermore, we gave dexamethasone (2 mg/day) instead of prednisolone (10 mg/day) for the next pregnancies of patients 3 to 5, beginning at 12 weeks of gestation. No fetal CCHB developed again.

Conclusions: For pregnant women with previous fetal immunologic CCHB, early initiation of dexamethasone instead of prednisolone might be effective to cross the placenta and avoid recurrences. Dexamethasone is also effective for fetal CCHB of early onset, fetal hydrops or heart failure. Observation only is suggested for nonimmunologic CCHB and remote or late-onset immunologic CCHB. Other modalities were tried for very sick fetuses, but their effectiveness was not predictable.