Heavy drinking during pregnancy is the cause of fetal alcohol syndrome, the leading known cause of mental retardation. Even moderate drinking during pregnancy can result in a spectrum of more subtle effects which are determined by both the dose of ethanol and the gestational age at the time of exposure. It is estimated that 1% of all newborns are affected by prenatal ethanol exposure. Identifying these alcohol exposed newborns is difficult. Currently there is no laboratory tool for their identification. A biological marker for low to moderate alcohol use (1-14 drinks/week) during pregnancy would be significant step forward. Preliminary research has shown that fatty acid ethyl esters, long lived non-oxidative metabolites of ethanol, in meconium may serve such a purpose. This proposal seeks to address the hypothesis that fatty acid ethyl esters in meconium are useful biological markers for exposure to low to moderate maternal ethanol use during pregnancy, by achieving the following three specific aims: 1) Determine a denominator to normalize the quantify of fatty acid ethyl esters between subjects. 2) Determining the half of fatty acid ethyl esters in vivo. 3) Using 3 variables, location within the meconium, the quantity and the fatty acid moiety, the quantity and gestational age at exposure can be determined. These studies will use a sheep model of alcohol related neurodevelopmental disorder. These studies will provide preliminary data to study the utility of this biomarker in a human population.