Blood levels of phosphatidylethanol in pregnant women reporting positive alcohol ingestion, measured by an improved LC-MS/MS analytical method.

Objective. A reliable biomarker of low alcohol exposure during pregnancy is needed to clarify the controversy on the teratogenicity of low-to-moderate alcohol levels. Methods. Blood samples were obtained from 13 pregnant women who self-reported alcohol ingestion between 2.5 and 20 drinks/week, and from 26 controls. Total lipids were extracted, and phosphatidylethanol (PEth) species 16:0/16:0, 16:0/18:1, and 16:0/18:1 were separated by high-performance liquid chromatography (HPLC) on a reverse-phase phenyl column. These PEth species were quantified by MS/MS using phosphatidylpropanol as internal standard, with electrospray ionization and MRM. Results. PEth species were not detected in women who abstained from alcohol ingestion during pregnancy, whereas PEth-16:0/18:1 was > 5 nmol/L in those with positive alcohol ingestion. PEth species were detected for up to 4 weeks after cessation of exposure. Conclusions. PEth-16:0/18:1 was detected in pregnant women at 4-6 weeks after their last low-to-moderate alcohol ingestion, and therefore appears to be a reliable biomarker of prenatal alcohol exposure to study the teratogenicity of alcohol at these exposure levels. [ABSTRACT FROM AUTHOR]