In recent years, fatty acid ethyl esters (FAEEs) in meconium emerged as reliable, direct biological markers for establishing gestational ethanol exposure. Among the minor nonoxidative products of ethanol metabolism, there are ethyl glucuronide (EtG) and ethyl sulfate (EtS).
The aim of the study was to analyse meconium specimens from two different Mediterranean cohorts to check for the presence of EtG and EtS, and to investigate the eventual correlation between meconium FAEEs and these two metabolites and their possible application as direct biomarkers of gestational ethanol exposure.
FAEEs, EtG and EtS were quantified by liquid chromatography tandem mass spectrometry in meconium samples obtained from the Neonatal Intensive Care Unit of Arcispedale Santa Maria Nuova, Reggio Emilia, Italy (N= 96) and from the Pediatric Service of the Hospital del Mar in Barcelona, Spain (N=81).
EtG was present in more than 80% meconium samples while EtS only in 50% specimens Although the samples from Spain and Italy originated from similar socio-demographic cohort, EtG values in the Barcelona samples (median value: 101.5 ng/g) were statistically higher than those from Reggio Emilia ones (median value: 15.6 ng/g). In the Barcelona cohort, EtG values could differentiate between samples with FAEEs below and those equal or above 2 nmol/g - the cut-off used to differentiate heavy maternal ethanol consumption during pregnancy from occasional or no use.
For the first time the presence of EtG and EtS in meconium has been proven, with EtG concentration likely to discriminate heavy maternal ethanol consumption during pregnancy disclosed by FAEEs concentration in this matrix. Further investigations are needed to verify the use of these two ethanol metabolites as alternative biomarkers of chronic in utero exposure to ethanol.
Keywords: Meconium, ethylglucuronide, ethylsulfate, FAEEs, gestational ethanol consumption