Preferential alcoholic embryopathy among contiguous siblings of Long-Evans rats.

Ethanol exposure alters sex steroidogenesis and sexually dimorphic behaviors in rodent offspring. Contiguity to siblings of the same or opposite sex in utero also affects steroidogenesis and sexual dimorphism in rodents. The present study with Long-Evans rats shows that maternal exposure to ethanol during the critical period of rodent organogenesis preferentially affects body weights and increases malformations in offspring dependent on their in utero contiguity to siblings of the opposite sex.