Detection of cocaine and its metabolites in human amniotic fluid.

The dramatic rise in maternal drug abuse and the incidence of positive drug findings during neonatal testing has increased the need for prenatal toxicological testing for drugs of abuse. Human amniotic fluid samples collected after 13-39 weeks of pregnancy were screened for cocaine metabolite (benzoylecgonine) by fluorescence polarization immunoassay (FPIA). All positive samples, as well as any accompanying maternal serum, were confirmed by gas chromatography/mass spectrometry (GC/MS) for cocaine and its metabolites. Five samples out of 450 were positive for cocaine, benzoylecgonine, and ecgonine methyl ester by GC/MS. In addition, one sample was also positive for cocaethylene. Two maternal serum samples were positive for benzoylecgonine and ecgonine methyl ester. The presence of cocaine, benzoylecgonine, ecgonine methyl ester, and cocaethylene in the amniotic fluid suggests that the fetus is exposed to cocaine and its metabolites through maternal circulation. The impact of this exposure on the health of the newborn is unknown.