Low dose alcohol contracts the human umbilical artery in vitro.

Beginning at very low concentrations (0.001 g/100 ml), alcohol elicited dose-dependent contractions of the human umbilical artery in vitro. Additionally, 16 of the 108 arteries tested had a 5-10-min spasm in response to alcohol. Alcohol (0.2 g/100 ml) also increased tension developed in response to all angiotensin II doses, but had no effect on serotonin-induced contractions. These results suggest that alcohol may increase umbilicoplacental resistance in vivo, thus decreasing fetal-placental blood flow.