Retrospective assessment of prenatal alcohol exposure by detection of phosphatidylethanol in stored dried blood spot cards: An objective method for determining prevalence rates of alcohol consumption during pregnancy

Aims: To analyze the efficacy of screening banked newborn dried blood spots (DBS) for detection of phosphatidylethanol (PEth), a direct alcohol biomarker, with the purpose of performing a retrospective assessment of statewide prevalence rates of alcohol consumption in late pregnancy that results in risky prenatal alcohol exposure. Design: Residual DBS samples collected for newborn screening and stored by a state department of public health were examined for concentrations of PEth. The prevalence of prenatal alcohol exposure, as determined by this direct alcohol biomarker, was compared to prevalence rates of alcohol consumption during pregnancy that have been derived from multiple state-based and national studies using maternal self-report surveys. Setting: DBS cards representative of the general newborn population were collected from multiple hospitals across a single midwestern state. Participants: Two hundred fifty anonymous newborn DBS collected for routine metabolic screening in a midwestern state were requested through the Virtual Repository of Dried Blood Spots. Measures: Concentrations of PEth, a highly specific biomarker of alcohol consumption, were analyzed using a liquid chromatography-tandem mass spectrometry method validated by our laboratory. Findings: Of 250 DBS examined, 4% were positive for PEth (PEth >= 8ng/ml) which is indicative of exposure to maternal alcohol consumption during the last month of pregnancy. Conclusions: Detection of PEth from newborn DBS cards can identify prenatal alcohol exposure and also be used for retrospective surveillance of alcohol consumption during the last three to four weeks of pregnancy, using specimens that are collected for routine metabolic screening and stored by many state health departments.