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

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.