Prenatal cocaine use associated with down regulation of receptors in human placenta.

Cocaine use during pregnancy has been associated with abruptio placentae and spontaneous abortions. These effects may be secondary to the vasoconstrictive effects of cocaine or to other alterations. Since it has been demonstrated that the use of opiates during pregnancy alters placental receptors, the effects of cocaine on placental receptors was studied. Women who used cocaine during pregnancy showed a significant lowering of the total number of beta-adrenergic receptor binding sites and delta-opiate receptor binding sites. The decreases in Bmax for each of these receptors was not associated with a decrease in the Kp. The potential causes for the receptor down regulation and effects are discussed.