Prenatal ethanol and stress in mice: 1. Pup behavioral development and maternal physiology

On days 12 to 17 of pregnancy, B6D2F1 mice were pair-fed liquid diets containing either 25% ethanol-derived calories or an isocaloric amount of maltose-dextrin. During this period, half the mice in each dietary condition also underwent two daily one-hour periods of restraint stress. A fifth group, given lab chow and water ad lib, was left undisturbed throughout gestation. Neither treatment affected offspring body weight on days 22 or 32 postconception, but undernutrition produced by the pair feeding procedure reduced day 32 body weight in all groups relative to the ad lib-fed group. Both prenatal ethanol and pair feeding led to delayed neurobehavioral development on day 32, while prenatal stress significantly reduced the degree of developmental delay caused by these factors. In a second study, restraint stress significantly reduced blood alcohol concentrations in pregnant dams on day 15 of gestation while elevating plasma corticosterone concentrations, and this elevation was consistent regardless of the dietary condition of the dam. The pair feeding procedure also produced corticosterone elevations but the effect of ethanol was not significant. These results suggest that prenatal stress in the presence of other physiological insults may act to counter the actions of those insults.