Use of terbutaline in the treatment of complete heart block in the fetus.

Between 1989 and 2000, 21 fetuses were diagnosed with complete atrioventricular block. Seven women with fetal ventricular rates of less than 60 were given oral terbutaline, and 6 of these had an initial increase in the fetal ventricular rate. Four fetuses (57%) maintained an increased average rate of 60 beats per minute and survived. Two fetuses returned to rates below 55 and died. The final fetus, with hypertrophic cardiomyopathy, was unresponsive. Terbutaline, therefore, is initially effective in raising the fetal ventricular rate, but this effect may be transient.