Background <p>Prenatal alcohol exposure (PAE) is a major public health concern, yet no reliable clinical tools are available for assessing levels of drinking during pregnancy. Fatty acid ethyl esters (FAEEs), the non-oxidative metabolites of ethanol in meconium, are potential biomarkers for quantifying PAE.</p> Methods <p>In a prospective birth cohort of children exposed to alcohol and drugs in utero, meconium from 216 newborns was analyzed. FAEE concentrations were quantified with gas chromatography via a flame ionization detector. A factor score was derived via a principal component analysis of six FAEE analytes. Expressive and receptive language were assessed in 189 children (56% girls) at ages 10 and/or 12.</p> Results <p>Higher FAEE factor scores were related to lower receptive language, with its harmful effect mitigated by non-kinship care at lower levels of FAEEs (<i>p</i> = 0.03). This relationship remained significant after adjusting for child IQ (<i>p</i> = 0.008). Expressive language showed a non-significant trend (<i>p</i> = 0.09), which disappeared after IQ adjustment (<i>p</i> &gt; 0.30). Other prenatal drug exposures were unrelated to the effects of FAEEs on language skills.</p> Conclusions <p>Elevated levels of FAEEs in meconium can be potential biomarkers for identifying newborns at risk for poor language development related to PAE.</p> Impact <p><UnorderedList Mark="Bullet"> <ItemContent> <p>Higher concentrations of Fatty acid ethyl esters (FAEEs), the non-oxidative metabolites of ethanol, analyzed in meconium, are associated with lower receptive language at 10 and 12 years of age, but their harmful effect was mitigated at lower levels of FAEEs by the more enriched caregiving environment of non-kinship care.</p> </ItemContent> <ItemContent> <p>Elevated levels of FAEEs in meconium can be potential biomarkers for identifying newborns at risk for poor language development related to prenatal alcohol exposure (PAE).</p> </ItemContent> <ItemContent> <p>FAEEs may provide diagnostic clarity for PAE, allowing the identification of moderate and episodic PAE, which is unlikely to be detected at birth.</p> </ItemContent> </UnorderedList></p>