Prenatal pyrethroid insecticide exposure and thyroid hormone levels and birth sizes of neonates.
Pyrethroid insecticides have been shown to possess thyroid hormone disrupting properties in previous animal studies. In this study, the relationship between maternal exposure to pyrethroid insecticides during pregnancy and neonatal thyroid hormone status (free thyroxine (fT4) and thyroid stimulating hormone (TSH) in whole blood) and birth sizes were explored in 147 mother-neonate pairs in Tokyo. The concentration of 3-phenoxybenzoic acid (3-PBA) in maternal urine, sampled in the first trimester of gestation, was used for pyrethroid exposure assessment. Neonatal fT4 and TSH were within the normal range except for one elevated TSH (but normal fT4) in a neonate. Multiple regression analyses with stepwise variable selection did not extract maternal 3-PBA as significant for neonatal fT4 and TSH, indicating that maternal pyrethroid exposure had no apparent effect on the neonatal thyroid hormone status of the neonate subjects. For birth weight and head circumference, maternal 3-PBA was selected as significant with a positive partial regression coefficient along with other factors known to increase birth sizes of neonates (gestational weeks or maternal BMI). It was not clear if this was causal because no biological mechanism was apparent.
Department of Environmental Studies, University of Tokyo, Kashiwanoha 5-1-5, Kashiwa, Chiba 277-8563, Japan.
Jie
J
Zhang
Department of Environmental Studies, University of Tokyo, Kashiwanoha 5-1-5, Kashiwa, Chiba 277-8563, Japan. Electronic address: junyosh@k.u-tokyo.ac.jp.
Jun
J
Yoshinaga
Department of Environmental Studies, University of Tokyo, Kashiwanoha 5-1-5, Kashiwa, Chiba 277-8563, Japan.
Aya
A
Hisada
National Institute for Environmental Studies, Onogawa 16-2, Tsukuba, Ibaraki 305-8056, Japan.
Hiroaki
H
Shiraishi
Department of Obstetrics and Gynecology, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa, Tokyo 142-8555, Japan.
Kazuhisa
K
Shimodaira
Department of Obstetrics and Gynecology, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa, Tokyo 142-8555, Japan.
Takashi
T
Okai
Japan Public Health Association, 2-10-1 Okura, Setagaya, Tokyo 157-8535, Japan.
Maiko
M
Koyama
Japan Public Health Association, 2-10-1 Okura, Setagaya, Tokyo 157-8535, Japan.
Noriko
N
Watanabe
Japan Public Health Association, 2-10-1 Okura, Setagaya, Tokyo 157-8535, Japan.
Emiko
E
Suzuki
Department of Psychiatry and Neurology, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa, Tokyo 142-8555, Japan.
Miyako
M
Shirakawa
Department of Psychiatry and Neurology, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa, Tokyo 142-8555, Japan.
Yumiko
Y
Noda
Department of Psychiatry and Neurology, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa, Tokyo 142-8555, Japan.
Yoko
Y
Komine
Department of Psychiatry and Neurology, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa, Tokyo 142-8555, Japan.
Nagako
N
Ariki
Department of Psychiatry and Neurology, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa, Tokyo 142-8555, Japan.
Nobumasa
N
Kato
D001724:Birth Weight; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007306:Insecticides / Q000097:blood*; D008297:Male; D018811:Maternal Exposure / Q000706:statistics & numerical data*; D011247:Pregnancy; D011722:Pyrethrins / Q000097:blood*; D013963:Thyroid Hormones / Q000097:blood*; D014041:Tokyo
D007306:Insecticides; D011722:Pyrethrins; D013963:Thyroid Hormones
Birth weight; Free thyroxine; Head circumference; Mother–neonate pair; Thyroid stimulating hormone; Urinary 3-phenoxybenzoic acid