Hexoprenaline tocolysis for intrapartum fetal distress and acidosis.

Hexoprenaline, a selective beta 2-sympathomimetic drug, was administered to 12 patients with severe distress in labor. The fetal distress was documented by fetal heart rate abnormalities in association with a fetal scalp blood pH of less than 7.20. The mean fetal scalp pH was 7.17 +/- 0.17 before treatment. A 7.5- to 10-micrograms intravenous bolus of hexoprenaline was followed by an intravenous infusion titrated to inhibit uterine contractions. According to protocol, all patients delivered by cesarean section approximately 40 minutes after the bolus injection. The mean cord blood pH was 7.31 +/- 0.06. No infant had a five-minute Apgar score of less than 8, and there were no significant maternal or fetal side effects.