Determination of the half-life of di(2-ethylhexyl) phthalate (DEHP) in a preterm neonate using blood transfusion as the source of intravenous exposure

• Clinically indicated blood transfusion led to significant increases in urinary concentrations of DEHP metabolites with patterns consistent with sentinel exposure. • The observed half-lives of DEHP metabolites in our study participant infant tended to be shorter than those reported in adults. In the neonatal intensive care unit (NICU), infants face treatments that convey high-dose exposure to phthalates, a family of ubiquitous endocrine-disrupting organic chemicals. Past research shows that NICU-based phthalate exposure, particularly exposure to di (2-ethylhexyl) phthalate (DEHP), is associated with increased risk of abnormal multisystem outcomes among preterm infants. Blood product transfusion is a recognized significant source of DEHP exposure in hospitalized patients. In this pilot study we collected serial urine samples from one preterm subject following a clinically indicated blood transfusion as a sentinel DEHP exposure. Each specimen was analyzed for DEHP metabolites via liquid chromatography coupled with triple quadrupole tandem mass spectrometry. The calculated half-lives of DEHP metabolites in this subject were generally shorter than reported for adults. Our pilot data demonstrate the need for future studies to estimate population-level half-lives of DEHP metabolites in preterm infants to allow for more accurate NICU-based DEHP source identification than possible with estimates of DEHP metabolism in adults. Source identification is critical to mitigate exposure in the highly vulnerable NICU population