Physiologic and biochemical effects of ritodrine therapy on the mother and perinate.

The materno-fetal and neonatal effects of ritodrine were studied in 37 women treated for premature labor with intravenous (i.v.) ritodrine. Marked cardiovascular, respiratory, and biochemical side effects of therapy were seen in the mothers and tachycardia was noted in the fetuses. The neonates of 18 women in whom ritodrine successfully postponed delivery were delivered with good Apgar scores and their admission vital signs and nursery courses were benign. Ritodrine failed to delay delivery more than a week in 19 mothers. There were no differences between their newborns and 20 control neonates in admission vital signs, blood gases, blood chemistries, complete blood counts, platelet counts, peak bilirubin, or duration of oxygen therapy. This study revealed no deleterious effects on neonates delivered after maternal ritodrine therapy despite significant maternal and fetal effects.