Prenatal ethanol and stress in mice: 2. Development and behavior of fostered offspring

On days 12 to 17 of gestation, B6D2F2 mice were pair-fed liquid diets containing either 25% ethanol-derived calories or an isocaloric amount of maltose-dextrin. During this time, half the mice in each dietary condition also underwent two daily one-hour periods of restraint stress. All pups were fostered at birth to untreated mothers whose pups, in turn, were fostered to the treated mothers. Two additional groups of untreated dams were included, the pups in one group being fostered to other untreated dams while the rest remained with their biological mothers. Prenatal ethanol retarded neurobehavioral development on day 32 postconception and also decreased pup body weight at birth and at weaning, and brain weight on day 32 and at weaning. Prenatal stress decreased body weight at birth in the pair-fed controls only, increased open field activity at weaning and affected retention of a learned passive avoidance task. Undernutrition due to the pair feeding procedure decreased pup birth weight. There were a few effects on untreated pups fostered to treated dams, but these were marginal. These results do not support a role of stress-induced physiological changes in ethanol teratogenicity.