ABSTRACT
Inhibition of preterm labor by tocolytic agents reduces the incidence of preterm birth.
Betamimetic drugs are the most widely used tocolytic. However, they are from time
totimecontraindicated, their administration involves potential risks for mother and
fetus, and their tocolytic effect is sometimes insufficient. Ethanol infused in intoxicating
doses was the first clinically useful tocolytic agent, but because of its potential
risks to the fetus, its use is now infrequent. We have examined the efficacy of ethanol
infused at much lower rates, alone or in combination with ritodrine, to inhibit preterm
uterine contractions. Fifty-four women between 20 and 36 weeks of gestation participated
in the study. In 14, betamimetics were contraindicated and they were given ethanol
alone. In 38, ritodrine infusions (0.2 gm/min) had failed to arrest preterm labor
and they were then given ethanol with ritodrine (0.2 gm/min) The dose of ethanol was
0.11 gm/kg/houron the average, which is approximately equivalent to the metabolic
rate. Altogether, 64 treatments were given, 14 with ethanol alone and 50 combined
with 0.2 gm/min ritodrine. In 81% of the treatments, contractions were suppressed
within 15.3 hours on the average. Preterm birth (infant less than 2500 gm) was prevented
in 70% of the patients. No adverse effects attributable to ethanol were observed.
Treatment with low-dose intravenous infusion of ethanol is a cheap, efficacious, and
low-risk method to stop preterm uterine activity and is clinically useful for prevention
of preterm birth. Possible mechanism of this effect is discussed.
