Teratogenesis after acute alcohol exposure in cultured rat embryos

In order to investigate whether alcohol has teratogenic properties, rat embryos were cultured in vitro during their organogenetic period and exposed to ethanol at 200-800 mg% culture medium for the 48 hours of culture (0-24 somite stage) or to 600-800 mg% for 24 hours, or 6-hour periods. Exposure to alcohol throughout the entire 48-hour culture period or the first 24-hour period (0-12 somites) produced marked growth retardation, particularly of the head region in a dose-dependent manner, but did not prevent neural tube closure. Exposure to high levels of ethanol during specific 6-hour periods of early organogenesis (three to nine somites) prevented closure of the neural tube in 30% of cultured rat embryos, indicating a direct teratogenic action of ethanol. These results implied an effect of ethanol on embryonic development, independent of maternal metabolism. The 6-hour exposure experiments demonstrated that high doses of ethanol during specific periods of organogenesis can be teratogenic.