The Associations of Urinary DEHP Metabolites in Pregnant Women with Serum Thyroid Hormone and Thyroid-Related Genes in Neonatal Umbilical Cord Blood in Jilin, China

Di-(2-ethylhexyl) phthalate (DEHP) is a widespread environmental endocrine disruptor, while maternal DEHP exposure may affect the thyroid function of newborns. The purpose of this study was to assess influential factors of DEHP level in maternal urine and associations between DEHP and serum thyroid hormones in cord blood and associations between DEHP and thyroid-related genes in cord blood. 300 pairs of pregnant women and newborns were included in the study. The levels of DEHP metabolites (MEHP, MEOHP, MEHHP, MCMHP, and MECPP) in urine were detected by high-performance liquid chromatography-tandem mass spectrometry. Serum hormones in cord blood were detected by Elisa kits. The levels of genes in cord blood were measured by quantitative real-time PCR. The independent-sample t-test, Mann–Whitney test, Spearman’s correlation, and multiple linear regression were used to evaluate the target associations. The detection rate of five DEHP metabolites was 100