The inhibitory effect of ethanol on oxytocin-induced labor at term.

Intravenous ethanol infusion significantly reduced oxytocin-induced uterine activity in pregnant patients at term. The dose response to oxytocin was linear when plotted log2 x in all patients studied, and the line was shifted to the right by alcohol, but the slope remained essentially unchanged. These results suggest that alcohol directly inhibits the effect of oxytocin on the myometrium, although the possibility of some central inhibition of oxytocin release cannot be discounted.