title: Maternal phthalate exposure during the first trimester and serum thyroid hormones in pregnant women and their newborns.
abstract: Animal and human studies have suggested that phthalate alters thyroid hormone concentrations. This study investigated the associations between phthalate exposure during the first trimester and thyroid hormones in pregnant women and their newborns. Pregnant women were enrolled from the prospective Ma'anshan Birth Cohort study in China. A standard questionnaire was completed by the women at the first antenatal visit. Seven phthalate metabolites were measured in one-spot urine at enrolment (10.0 ± 2.1 gestational weeks), as were thyroid hormone levels in maternal and cord sera. Multivariable linear regression showed that 1-standard deviation (SD) increase in natural log (ln)-transformed mono(2-ethylhexyl) phthalate (MEHP) and mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) was associated with 0.163 μg/dL (p = 0.001) and 0.173 μg/dL (p = 0.001) decreases in maternal total thyroxine (TT4). Both MEHP and MEHHP were negatively associated with maternal free thyroxine (FT4; β: -0.013, p < 0.001 and β: -0.011, p = 0.001, respectively) and positively associated with maternal thyroid-stimulating hormone (β: 0.101, p < 0.001; β: 0.132, p < 0.001, respectively). An inverse association was observed between monobenzyl phthalate and maternal TT4 and FT4. A 1-SD increase in ln-transformed monoethyl phthalate was inversely associated with maternal TT4 (β: -0.151, p = 0.002). By contrast, the concentrations of phthalate metabolites in urine were not associated with those of thyroid hormone in cord serum. Our analysis suggested that phthalate exposure during the first trimester disrupts maternal thyroid hormone levels.
authors.affiliation: Department of Maternal, Child and Adolescent Health, School of Public Health, Anhui Medical University, Hefei, Anhui, China.
authors.forename: Hui-Yuan
authors.initials: HY
authors.lastname: Yao
authors.affiliation: Department of Maternal, Child and Adolescent Health, School of Public Health, Anhui Medical University, Hefei, Anhui, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Han
authors.affiliation: Department of Maternal, Child and Adolescent Health, School of Public Health, Anhui Medical University, Hefei, Anhui, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Gao
authors.affiliation: Department of Maternal, Child and Adolescent Health, School of Public Health, Anhui Medical University, Hefei, Anhui, China.
authors.forename: Kun
authors.initials: K
authors.lastname: Huang
authors.affiliation: Department of Maternal, Child and Adolescent Health, School of Public Health, Anhui Medical University, Hefei, Anhui, China.
authors.forename: Xing
authors.initials: X
authors.lastname: Ge
authors.affiliation: Department of Maternal, Child and Adolescent Health, School of Public Health, Anhui Medical University, Hefei, Anhui, China.
authors.forename: Yuan-Yuan
authors.initials: YY
authors.lastname: Xu
authors.affiliation: Ma'anshan Maternal and Child Health (MCH) Center, Ma'anshan, China.
authors.forename: Ye-Qing
authors.initials: YQ
authors.lastname: Xu
authors.affiliation: Anhui Provincial Key Laboratory of Population Health & Aristogenics, Hefei, China.
authors.forename: Zhong-Xiu
authors.initials: ZX
authors.lastname: Jin
authors.affiliation: Anhui Provincial Key Laboratory of Population Health & Aristogenics, Hefei, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Sheng
authors.affiliation: Ma'anshan Maternal and Child Health (MCH) Center, Ma'anshan, China.
authors.forename: Shuang-Qin
authors.initials: SQ
authors.lastname: Yan
authors.affiliation: Department of Maternal, Child and Adolescent Health, School of Public Health, Anhui Medical University, Hefei, Anhui, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Zhu
authors.affiliation: Department of Maternal, Child and Adolescent Health, School of Public Health, Anhui Medical University, Hefei, Anhui, China. Electronic address: jia7218@126.com.
authors.forename: Jia-Hu
authors.initials: JH
authors.lastname: Hao
authors.affiliation: Department of Maternal, Child and Adolescent Health, School of Public Health, Anhui Medical University, Hefei, Anhui, China; Anhui Provincial Key Laboratory of Population Health & Aristogenics, Hefei, China. Electronic address: fbtao@126.com.
authors.forename: Fang-Biao
authors.initials: FB
authors.lastname: Tao
mesh_terms: D000328:Adult; D001711:Biotransformation; D002681:China; D004051:Diethylhexyl Phthalate / Q000652:urine; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D018811:Maternal Exposure; D010795:Phthalic Acids / Q000378:metabolism / Q000494:pharmacology* / Q000652:urine; D011247:Pregnancy; D011261:Pregnancy Trimester, First / Q000378:metabolism*; D011446:Prospective Studies; D013963:Thyroid Hormones / Q000097:blood*; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood
chemical_list: D010795:Phthalic Acids; D013963:Thyroid Hormones; C479069:mono(2-ethyl-5-hydroxyhexyl) phthalate; C581825:monoethyl phthalate; C032279:phthalic acid; D013972:Thyrotropin; D004051:Diethylhexyl Phthalate; D013974:Thyroxine
keywords: Endocrine disruption; Newborn; Phthalate; Pregnancy women; Thyroid hormone; Urinary metabolites