Department of Human Ecology, School of International Health, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan.
Int J Environ Res Public Health. 2022 Oct 13;19(20):13177. doi: 10.3390/ijerph192013177.
Thyroid functioning is an integral part of the endocrine system that supports conception and pregnancy. Frequent consumption of seafood and iodine by Japanese people may adversely affect their thyroid function. Thus, in this study, we aimed to analyze the associations between iodine intake, thyroid hormones, autoimmunity, and natural conception rates in Japanese women trying to conceive their first child. A prospective study of 24 weeks targeted 80 women with no history of infertility, who did not plan to undergo fertility treatment. Concentrations of urinary iodine concentration and thyroid biomarkers in the serum at enrollment were measured. Thirty-five women naturally conceived during the follow-up. The median (inter-quartile range) urinary concentration of iodine was 297 (165, 500) μg/L. Free triiodothyronine (T3) and free thyroxin (T4) negatively correlated with urinary iodine concentrations. Women with anti-thyroid peroxidase (anti-TPO) ≥ 16 IU/mL had lower conception rates (hazard ratio: 0.28, 95% confidence interval, 0.08-0.92) compared with those with anti-TPO < 16 IU/mL, after adjusting for age and coital frequency. None of anti-thyroglobulin antibody, free T3, free T4, or thyroid-stimulating hormone showed significant associations with conception rate after adjusting for age and coital frequency. The negative association between thyroid autoimmunity and natural conception rates warrants further investigation.
甲状腺功能是内分泌系统的一个组成部分，它支持受孕和妊娠。日本人经常食用海鲜和碘，这可能会对他们的甲状腺功能产生不利影响。因此，在这项研究中，我们旨在分析碘摄入量、甲状腺激素、自身免疫与试图生育第一胎的日本女性自然受孕率之间的关系。一项为期 24 周的前瞻性研究纳入了 80 名无不孕史且不计划接受生育治疗的女性。在入组时测量了血清中尿碘浓度和甲状腺生物标志物的浓度。在随访期间，有 35 名女性自然受孕。尿碘浓度的中位数（四分位数间距）为 297（165，500）μg/L。游离三碘甲状腺原氨酸（T3）和游离甲状腺素（T4）与尿碘浓度呈负相关。与抗甲状腺过氧化物酶（anti-TPO）<16 IU/mL 的女性相比，anti-TPO≥16 IU/mL 的女性受孕率较低（风险比：0.28，95%置信区间：0.08-0.92），校正年龄和性交频率后。校正年龄和性交频率后，抗甲状腺球蛋白抗体、游离 T3、游离 T4 或促甲状腺激素与受孕率均无显著相关性。甲状腺自身免疫与自然受孕率之间的负相关关系值得进一步研究。
