Measurement of drugs in neonatal hair; a window to fetal exposure

Because the hair neonates are born with grows during the last 3 months of pregnancy, the presence of drugs (e.g. cocaine) or environmental toxins (e.g. nicotine) reflects fetal exposure to such compounds. In the case of cocaine, hair measurement are several fold more sensitive than maternal history or urine measurements. Measurements of cotinine in neonatal hair are capable of distinguishing between fetal exposure to passive versus active smoking. Because most cocaine users also smoke cigarettes, neonatal measurements of both cocaine and cotinine will allow cumulative quantification of fetal risk.