AUTHOR=Fan Pianpian , Chen Yuanzhi , Luo Zhong-Cheng , Shen Lixiao , Wang Weiye , Liu Zhiwei , Zhang Jun , Ouyang Fengxiu 

TITLE=Cord Blood Thyroid Hormones and Neurodevelopment in 2-Year-Old Boys and Girls

JOURNAL=Frontiers in Nutrition

VOLUME=Volume 8 - 2021

YEAR=2021

URL=https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2021.773965

DOI=10.3389/fnut.2021.773965

ISSN=2296-861X

ABSTRACT=Objectives: Thyroid hormones are essential for neurodevelopment in early life. However, the impact of mild alterations in neonatal thyroid hormones on infant neurodevelopment and its sex-dimorphism is unclear. We aimed to assess whether mild variations in neonatal thyroid hormones of euthyroid mother are related to neurodevelopment in 2-year-old boys and girls. 
Methods: This study used  data from 452 singleton term-born infants of mothers with normal thyroid function in Shanghai, China, and their follow-up measure at age 2 years. Cord serum concentrations of free triiodothyronine (FT3), free thyroxine (FT4), thyroid stimulating hormone (TSH), and thyroid peroxidase antibody (TPOAb) were measured by chemiluminescent microparticle immunoassays, and classified into three groups: the low (1st, Q1), middle (2nd-4th, Q2-Q4), and high (5th, Q5) quintiles. The neurodevelopment indices were assessed by Ages & Stages Questionnaire, third edition (ASQ-3) at age 24 months. 
Results: Compared to infants with thyroid hormones in the middle(Q2-Q4), boys with FT4 in the lowest quintile had 5.08 (95%CI: 1.37,8.78) points lower scores in communication, 3.25 (0.25,6.25) points lower scores in fine motor, and 3.84 (0.04, 7.64) points lower scores in personal-social domains, respectively. Boys with FT3 in the highest quintile had 4.48 (0.83,8.14) points increases in personal-social domain. These associations were not statistically significant in girls.
Conclusions: Mild alterations in thyroid hormones of newborns were associated adversely with neurodevelopment in boys, suggesting the importance of optimal thyroid hormones status for neurodevelopment in early life.