Phosphatidylethanol Levels in Postpartum Women and Their Newborns in Uruguay and Brazil

Background: There is increasing interest in the development of newborn screening tests to identify children at risk of fetal alcohol spectrum disorder (FASD) in order to provide these children with early intervention. Phosphatidylethanol (PEth) has emerged as a potential universal newborn screening candidate. Methods: The aim of this report was to present the results of a study designed to compare PEth levels in 1,140 postpartum women and their newborn infants in Montevideo, Uruguay, and Sao Paulo, Brazil. Self-report alcohol use during pregnancy data was collected, along with both maternal and newborn dried blood spot samples for PEth analysis. Results: The average age and parity of the women in the sample were 26 years of age and 2.3 pregnancies. For the Uruguay sample (n = 611), 45.8% of postpartum women had PEth levels ≥ 8 ng/ml with a mean positive PEth of 43.6 ng/ml. In contrast, 86.8% of the newborns had PEth levels ≥ 8 ng/ml, with a mean positive PEth of 77.4 ng/ml. For the Brazil sample (n = 529), 33.2% of women had PEth levels ≥ 8 ng/ml with a mean positive PEth of 31 ng/ml. In contrast, 76.9% of the Brazil newborns had PEth levels ≥ 8 ng/ml and 43.9% with a mean positive PEth of 61.1 ng/ml. PEth levels were significantly higher in newborns compared with their postpartum mothers in both the Uruguay and Brazil samples. Self-reported third-trimester alcohol was 6% in the Uruguay sample and 9.1% in the Brazil sample compared with positive maternal PEth levels in 45.8% and 33.2%, respectively. Conclusions: Clinicians may want to consider newborn PEth screening in high-risk populations where prenatal alcohol use is common. The mechanism underlying significantly higher PEth levels in newborns compared with their mothers is not known.