The effect of the beta-mimetic drug clenbuterol on maternal and fetal behaviour.

The effect of the beta-mimetic compound clenbuterol on maternal and fetal behaviour was studied in 12 normal primigravidae between 35 and 38 wk of gestation. None of the subjects exhibited any signs of uterine activity. Following a control period of 60 min, oral intake of 100 micrograms of clenbuterol resulted in a maximum increase in maternal and fetal heart rate of 13 and 7%, respectively. Maternal systolic blood pressure showed a rise of 6%, whereas diastolic blood pressure demonstrated a drop of 8%. The percentage incidence of fetal breathing and trunk movements did not show any significant change following oral clenbuterol administration, indicating the absence of any major effect of this drug on the fetal central nervous system. Maternal blood glucose levels demonstrated a fairly constant pattern during the entire study period.