Testing ethylglucuronide in maternal hair and nails for the assessment of fetal exposure to alcohol: comparison with meconium testing

Background: The deleterious effects exerted by prenatal ethanol exposure include physical, mental, behavioral, and/or learning disabilities that are included in the term fetal alcohol spectrum disorder. The measurement of ethylglucuronide (EtG) in alternative biological matrices, including neonatal and maternal hair, neonatal meconium, and maternal nails, is receiving increasing interest for the accurate evaluation of the in utero exposure to alcohol. Objective: To evaluate the correlation between EtG in maternal hair and nails with EtG in neonatal meconium to further explore the suitability of these biomarkers in disclosing prenatal exposure to ethanol. Methods: A total of 151 maternal hair strands (0-6 cm), nail clips (2-6 mm), and corresponding neonatal meconium and nails samples were obtained from neonatal wards of 4 Mediterranean public hospitals: Rome, Florence, and Belluno in Italy and Barcelona in Spain. Hair, nails, and meconium were analyzed for the presence of EtG by validated liquid chromatography mass spectrometry assay. Meconium was also analyzed for the presence of fatty acid ethyl esters (FAEEs) as a complementary biomarker of potential in utero exposure to alcohol. Results: Eighteen newborns resulted in utero exposed to maternal alcohol consumption by FAEE testing in meconium with EtG values between 0.5 and 1.5 nmol/g. Unfortunately, none of these cases were confirmed by the presence of EtG in maternal hair and nails samples, which resulted all negative to this biomarker. Discussion and Conclusions: The results confirm that FAEEs and EtG in meconium are the best biomarkers to assess in utero exposure to maternal alcohol. EtG in hair and nails are not good biomarkers to disclose alcohol consumption lower than on daily basis and lower than 1-2 alcoholic units per day