Effects of pregnancy and nutritional status on alcohol metabolism.

Metabolism of alcohol (i.e., ethanol) is regulated by genetic and environmental factors as well as physiologic state. For a given alcohol intake, the rate of alcohol clearance, which ultimately determines tissue ethanol concentrations, may be the most significant risk factor for many of the detrimental effects of alcohol. Faster ethanol clearance would help minimize target tissue concentrations, and in pregnant women, mitigate fetal alcohol exposure. Much remains to be known about the effects of the altered endocrine milieu of pregnancy on alcohol metabolism and clearance in the mother. Research has shown that among pregnant rats allowed unrestricted access to alcohol and those fed alcohol containing liquid diets under experimental conditions via a feeding tube (total enteral nutrition [TEN]), urine ethanol concentrations (and thus blood and tissue ethanol concentrations) are lower in pregnant rats compared with non-pregnant females given the same dose of ethanol. Maternal nutritional status also is an important determinant of fetal alcohol toxicity. Research using the TEN system has demonstrated that alcohol-induced fetal growth retardation is potentiated by undernutrition in part via impaired alcohol metabolism and clearance.