Meconium Fatty Acid Ethyl Esters and Prediction of Fetal Alcohol Effects

easurement of fatty acid ethyl esters (FAEE) in meconium is a relatively novel biomarker to detect heavy prenatal alcohol exposure. As a biomarker of exposure, FAEEs have been shown to have high sensitivity and specificity. Recent studies have also evaluated the ability of FAEEs in meconium to predict adverse outcomes associated with fetal alcohol spectrum disorder (FASD). This article will review the current literature concerning the predictive value of FAEEs in meconium in identifying adverse fetal effects. Analysis of the ability of FAEEs in meconium to predict fetal alcohol effects is critical in evaluating the qualities of this new screening tool in the general population. In the first report, a population based study in Hawaii (n=422), Derauf et al. performed multiple logistic regression analysis to assess the association between FAEEs in meconium and different fetal outcomes. The regression allowed for control of factors that may affect fetal outcome such as other illicit drug use, which was also tested for in meconium. Total FAEE present in meconium was associated with lower one-minute Apgar scores measured at one-minute (p=0.003). Additionally, ethyl oleate was associated with decreased birth weight (<2500g) (p=0.006). No association was found between other fetal outcomes such as head circumference, birth weight (as a continuous variable), gestational age, or recumbent length. The positive cutoff for cumulative FAEEs used in this study was 50ng/gram meconium. This value is tenfold lower than the current cutoff of 500ng/gram meconium that is currently used by the US Drug Testing Laboratory, the laboratory where the meconium samples were analyzed for this study. Using the current, higher positive cutoff could possibly result in stronger associations since it would increase the specificity of the test. In a second report, a prospective study by Noland et al., 316 children completed executive functioning (EF) tasks at 4 years of age. The test included working memory, ability to plan, focus attention, and inhibitory control and relies on the functioning of the frontal-subcortical circuit. The three EF tasks performed in this study included category fluency, motor planning, and tapping inhibition. A child was considered alcohol exposed if FAEE levels were significantly greater than levels reported in an abstaining population from Jordan. Alcohol exposed children had a significantly lower tapping inhibition score (t=2.34 df=171) than non-exposed (defined by both a negative meconium test and maternal selfreport). There was no difference regarding the motor-planning and category fluency tasks but the authors propose that the abilities required for these two tasks may not be developed enough by the age of 4 to detect differences between the groups. Alcohol exposure remained a significant predictor of tapping inhibition performance after determining potential confounders, including current home environment and other prenatal drug exposures. The alcohol-exposed group also had lower birth weight, birth length, and head circumference. Furthermore, lower means for fullscale, verbal, and performance IQs were implied, although these did not reach statistical significance (p<0.08, p<0.1, p<0.1 respectively). An additional paper and abstract have been published reporting outcomes measured in the same cohort of children as the previous study by Noland et al. Performance on attention tasks that are under control of the frontal-striatal system was not affected by alcohol exposure (n=330). However, Peterson et al. determined a significant association between specific FAEEs and decreased psychomotor performance in children at age 2 (n=202) (p=0.01-0.04). Psychomotor performance was measured by the psychomotor developmental index scores of the Bayley Scales of Infant Development. No association was shown at 6.5 months and 1 year assessments. In a recent abstract by Jacobson et al., ethyl oleate had a stronger relation to infant cognitive performance on recognition memory and processing speed on the Fagan Test of Infant Intelligence than did maternal self report (n=55). M