Acetaldehyde production and transfer by the perfused human placental cotyledon

Fetal injury associated with maternal ethanol ingestion is a major cause of congenital anomalies and mental retardation. Studies with animals suggest that acetaldehyde, the primary hepatic oxidative metabolite of ethanol, may contribute to fetal damage. It is not known, however, whether acetaldehyde reaches the human fetus, either by placental production or transfer. Studies utilizing the perfused human placental cotyledon show that the human placenta oxidizes ethanol to acetaldehyde, releasing it into the fetal perfusate. Moreover, when acetaldehyde is present in the maternal perfusate, it is transferred to the fetal side, reaching approximately 50 percent of the maternal level. These findings suggest that the human placenta may play a pivotal role in the pathophysiology of ethanol-associated fetal injury.