ABSTRACT
Intrauterine drug exposure, and later, postnatal drug exposure, are important and complex phenomena with potentially serious medical, socio-economic, and legal consequences. Testing the newborn becomes extremely important for the identification of intrauterine drug exposure. The methods of testing in the pediatric population are similar to those used for the adult subjects; however, certain guidelines have to be followed especially for testing in newborns. Hair testing in the newborn should be performed with certain caveats in mind. First, the hair sample is very small; most infants are born with very little hair, and mothers are understandably reluctant to give permission to cut even a few strands of hair. Because of the scarcity of the hair, sensitive methods are needed for the analysis. Second, the concentration of drugs and their metabolites in the newborn hair can be sometimes much lower than in adult hair. Hair testing in children to document external contamination should be performed by the same methods as in adults.
