Effect of alcohol intoxication during pregnancy on foetal and placental weight: experimental studies

Recent animal studies have shown that alcohol intoxication in utero leads to a decrease in foetal weight and an increase in that of placenta. These findings are not, however, satisfactorily explained. The object of this study was to investigate these two effects, using inhalation of various concentrations of ethanol vapour as a method of intoxication. Three groups of 12 gravid female rats (treated groups) were intoxicated by permanent exposure to an alcohol atmosphere (19, 20 or 21 mg/l.). Three control groups of 12 gravid females were not intoxicated but had their diet reduced to the same energy intake as the treated groups. On day 21 of pregnancy, foetuses and placentas were surgically removed and individually weighed. The body-weight of foetuses was found to be lower in the treated groups than in the respective controls. Additionally the reduction of foetal weight was directly related to the severity of intoxication. Increases in placental weight were observed in the three intoxicated groups. The differences observed between foetal and placental weights may be interpreted as a foeto-protective phenomenon.