Testing for drugs of abuse in meconium of newborn infants

A reliable and sensitive screening procedure has been developed for drugs of abuse (amphetamines, cocaine metabolites, opiates, and phencyclidine [PCP]) in meconium from infants. The substances in meconium were extracted with chloroform-isopropanol (3:1) and screened by enzyme multiplied immunoassay technique (EMIT). The lower detection limits of the EMIT for benzoylecgonine, d-methamphetamine, morphine, and PCP were 250 ng/g, 730 ng/g, 110 ng/g, and 100 ng/g, respectively. This method was applied to meconium from 50 infants born to mothers suspected of using the drugs of abuse during pregnancy. Of the 50, 12 were positive for benzoylecgonine, seven for opiates, and one for PCP. The presence of benzoylecgonine and PCP in meconium was confirmed by gas chromatography/mass spectrometry and that of opiates by thin-layer chromatography. The routine analysis of meconium for drugs of abuse is recommended in cases where (A) urine can not be obtained or (B) urinalysis is negative for the substances despite a strong suspicion of maternal use of the substances during pregnancy.