Terbutaline: effects on the fetal heart at term.

The aims of this study were to evaluate the cardiac effects of subcutaneous terbutaline on the mother and fetus. Terbutaline was given in 250 or 500 μg doses to term gravidas not in labor. The mean arterial pressure (MAP), pulse, and uterine activity were measured. The fetal heart rate (FHR), accelerations, and decelerations were recorded. There were significant increases in maternal heart rate, FHR, and FHR accelerations, and a decrease in uterine basal activity after 500 μg, but not significantly after 250 μg of terbutaline. MAP was not significantly increased with either dose, although a small mean increase was observed. Terbutaline has a direct effect on the fetal heart apart from the effect of uterine relaxation.