Administration schedule for an ethanol-containing diet in pregnancy affects types of offspring brain malformations

In the present study, we administered liquid diets containing ethanol to pregnant rats on different schedules, and examined the cerebral cortex of their pups on gestational day (GD) 21 by immunohistochemistry. The first group of pregnant rats was fed a liquid diet containing 5% (w/v) ethanol during GDs 10-21(5% Et). The second group was fed a liquid diet containing 2.5% (w/v) ethanol on GDs 10-12, a diet containing 4% (w/v) ethanol on GDs 13-15, and a diet containing 5% (w/v) ethanol on GDs 16-21 (2.5-5% Et). Pups of 5% Et dams had leptomeningeal heterotopias mainly in the parietal cortex. In 2.5-5% Et pups, other types of malformations such as grooves, microgyri, stacked-up cortices, and defects of layer I were found. The diet intake and body weight gain of 2.5-5% Et dams were significantly higher than those of 5% Et dams during GDs 11-16. There was no difference in total ethanol consumption during GDs 10-21 between the two groups. However, ethanol consumption on GD 15 in 2.5% Et was higher than in 5% Et. A different schedule for administration of an ethanol-containing diet in pregnancy might induce different types of cerebral malformations in rat fetuses.