Ethanol and acetaldehyde concentrations in the rat foeto-maternal system after an acute ethanol administration given...

The metabolization curves for both ethanol and acetaldehyde after an acute intragastric or intravenous administration to the mother, have been studied. Metabolization of ethanol followed a very similar pattern in both the pregnant and their control virgin rats, whereas the levels of acetaldehyde derived from the metabolism of the administered ethanol were significantly higher in the pregnant animals, this fact implying that, in late gestation, there is a decrease in the mother's capacity for acetaldehyde metabolism. At the foetal side of the placenta, 150 min after the administration, the concentration of ethanol was similar to that found in the mother's circulation, thus proving a fluid transit of this metabolite through the placenta. The concentration of acetaldehyde in the foetus was relatively high, after the intragastric administration of the ethanol dose; we conclude that at certain ethanol concentrations, acetaldehyde can cross the rat placenta.