probably secondary to an increase in
maternal plasma norepinephrine, which increases uterine contractility,
constricts placental vessels, and decreases blood flow to the fetus.
Placental abruption accounts for 2% to 15% of adverse effects of cocaine
use during pregnancy. Abruption is thought to be caused by vasospasm
and hypoxia of the placental bed, and it is more common with cocaine
binging than with regular use. As a result of maternal cocaine use and
placental abruption, the incidence of stillbirth in cocaine-abusing
mothers is elevated 8% above the expected level when compared to the
general population