Effects of prenatal phthalate exposure on thyroid hormone levels, mental and psychomotor development of infants: The Hokkaido Study on Environment and Children's Health.
Di (2-ethylhexyl) phthalate (DEHP) is commonly used phthalates and concerns of adverse effects of prenatal DEHP exposure on neonatal thyroid hormone (TH) and neurodevelopment are increasing. However, there is no report regarding association between prenatal DEHP exposure and infant neurodevelopment including TH levels in Japanese population. Thus the aim of present study was to evaluate the associations between prenatal DEHP exposure and mental and psychomotor development of infants 6 and 18months along with investigating influence on neonatal free thyroxine (FT4) and thyroid stimulating hormone (TSH) levels in the prospective birth cohort study. Maternal blood samples collected between 23 and 41weeks of gestation was analyzed for mono (2-ethylhexyl) phthalate (MEHP), metabolite of DEHP levels. Neonatal FT4 and TSH were obtained from mass screening data. Infant neurodevelopment was assessed by Bayley Scale of Infant Development second edition at 6 and 18month of age. For the final analysis, 328 participants were included. The median levels of maternal MEHP was 10.6ng/ml, neonatal TSH and FT4 was 2.20 μU/ml and 2.03ng/ml, respectively. We did not find any associations between prenatal DEHP exposure and neonatal TH levels or infant mental and psychomotor development at 6 and 18month. In this study, prenatal DEHP exposure did not show adverse effects on infant TH levels or mental and psychomotor development in early life stage. However, our previous study revealed negative effects of prenatal DEHP exposure on sex hormone levels, continuous investigation on neurodevelopment in later life in association with prenatal DEHP exposure is necessary.
Center for Environmental and Health Sciences, Hokkaido University, Kita 12, Nishi 7, Kita-ku, Sapporo 060-0812, Japan.
Machiko
M
Minatoya
School of Health Sciences, Sapporo Medical University, Minami 1, Nishi 17, Chuo-ku, Sapporo 060-0061, Japan.
Sonomi
S
Naka Jima
Department of Public Health, Graduate School of Medicine, Hokkaido University, Kita 15, Nishi 7, Kita-ku, Sapporo 060-8638, Japan.
Seiko
S
Sasaki
Center for Environmental and Health Sciences, Hokkaido University, Kita 12, Nishi 7, Kita-ku, Sapporo 060-0812, Japan.
Atsuko
A
Araki
Center for Environmental and Health Sciences, Hokkaido University, Kita 12, Nishi 7, Kita-ku, Sapporo 060-0812, Japan.
Chihiro
C
Miyashita
Center for Environmental and Health Sciences, Hokkaido University, Kita 12, Nishi 7, Kita-ku, Sapporo 060-0812, Japan.
Tamiko
T
Ikeno
College of Life and Health Sciences, Chubu University, 1200 Matsumoto-cho, Kasugai 487-8501, Japan.
Tamie
T
Nakajima
College of Life and Health Sciences, Chubu University, 1200 Matsumoto-cho, Kasugai 487-8501, Japan.
Yuko
Y
Goto
Center for Environmental and Health Sciences, Hokkaido University, Kita 12, Nishi 7, Kita-ku, Sapporo 060-0812, Japan. Electronic address: rkishi@med.hokudai.ac.jp.
Reiko
R
Kishi
D000067576:Child Health; D004051:Diethylhexyl Phthalate / Q000633:toxicity*; D004785:Environmental Pollutants / Q000633:toxicity*; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007564:Japan; D008297:Male; D065886:Neurodevelopmental Disorders / Q000139:chemically induced*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000139:chemically induced*; D011446:Prospective Studies; D011596:Psychomotor Disorders / Q000139:chemically induced*; D013972:Thyrotropin / Q000097:blood*; D013974:Thyroxine / Q000097:blood*
D004785:Environmental Pollutants; D013972:Thyrotropin; D004051:Diethylhexyl Phthalate; D013974:Thyroxine
Di (2-ethylhexyl) phthalate; Neurodevelopment; Prenatal Exposure; Thyroid hormone