Successful prenatal treatment of congenital heart block with ritodrine administered transplacentally

Congenital heart block (CHB) is rather rare, and a poorer prognosis has been documented in fetuses with a ventricular rate <55 beats per minutes (bpm), in which therapeutic interventions during pregnancy have been warranted. We present a case of CHB associated with maternal anti-SSA/Ro antibody, diagnosed at 28 weeks' gestation. Fetal echocardiography revealed atrioventricular dissociation, with an atrial rate of 170 bpm and a ventricular rate of 54 bpm. To increase the fetal heart rate, maternal intravenous ritodrine infusion was undertaken, fetal ventricular rate was rapidly increased to 65 bpm. The pregnancy successfully continued until term, and a female infant weighing 2919 g was delivered by cesarean section with Apgar scores of 8 and 8 and 1 and 5 min. The infant is now 12 months of age and growing normally on oral terbutaline without pacing. In a case of fetal heart block, maternal administration of ritodrine may be a therapeutic intervention to improve the fetal and neonatal prognosis.