A randomized controlled study was carried out at three medical centers to compare the efficacy and side effects of
ethanol and
ritodrine in the treatment of threatened
premature labor. One hundred and thirty-five patients judged to be between the twentieth and thirty-sixth week of gestation and presenting with clinical symptoms of
premature labor were included. Sixty-seven patients were treated with
intravenous infusion of 10 per cent
ethanol. Sixty-eight patients were treated with
intravenous infusion of
ritodrine for 12 hours followed by oral
ritodrine. If labor recurred prematurely, up to two additional courses of
ethanol or
ritodrine were given. Delivery was postponed for more than 72 hours in 49 of 67 patients (73 per cent) with
ethanol and in 61 of 68 patients (90 per cent) with
ritodrine; this difference was significant. Patients in the
ethanol group gained a mean of 27.6 days while patients in the
ritodrine group gained a mean of 44.0 days. Fifty-four per cent of the
ethanol group and 72 per cent of the
ritodrine group carried their infants to 36 weeks of gestation. Five infants in the
ethanol group and one infant in the
ritodrine group died from
respiratory distress syndrome. The most frequent side effect of
ethanol were
nausea and
vomiting. The most frequent side effects of
ritodrine were
tachycardia and blood pressure changes which were easily controlled by lowering the infusion rate.
Ethanol and
ritodrine were both found to be effective inhibitors of
premature labor with
ritodrine giving the most favorable results.