Disposition of barbiturates in maternal blood, fetal blood, and amniotic fluid

Maternal ingestion of ortho-aminoacetophenone during gestation affects intake by offspring

Ingested flavor chemicals cross the placental barrier and occur in the fetal blood and amniotic fluid. This occurrence is detectable by the fetus, and can influence post parturition feeding. In the present experiment, pregnant mice were offered either 0.1% ortho-aminoacetophenone emulsions (OAP) or water throughout gestation. OAP is normally avoided by mice, apparently on the basis of chemosensory characteristics. Subsequently, offspring were offered 0.5%, 0.25%, or 0.1% OAP in one-bottle tests at 26 or 88 days of age. Offspring of mothers given OAP drank greater amounts of OAP than did offspring of mothers given water. Enhanced acceptance of OAP was not detected in mice exposed to 0.1% OAP as adults for a duration similar to that given during gestation. We conclude that fetal experiences with OAP lowered sensitivity and/or raised tolerance for the compound.

Current concepts of amniotic fluid dynamics

Amniotic fluid at term in the human is the product of numerous exchanges with the fetal and indirectly, the maternal compartments. Our current information on the formation, circulation, and removal of this fluid is limited but provides an interesting concept of the steady-state regulation of this space. Further confirmation of this model comes from data describing drug exchange between mother, fetus, and amniotic fluid.