This study aims to evaluate the relationship between subclinical hypothyroidism (SCH) during the first trimester and gestational diabetes mellitus (GDM) that was happened later on in our cohort. A total of 6530 pregnant women who first visited before 13+6 gestational weeks and accepted routinely prenatal services in the third affiliated hospital of Sun Yat-Sen University from January 2015 to September 2018 were finally met the inclusion criteria and recruited. Thyroid functions were performed at the first visit and a 2h 75-g OGTTwas performed between 24-28 weeks. The glucose levels of OGTT were shown no differences between SCH and euthyroid women [0 hour: 4.17 mmol/L (3.99-4.38) vs. 4.16 mmol/L (3.97-4.39), P = 0.730; 1 hour: 7.61 mmol/L (6.64-8.66) vs. 7.68 mmol/L (664-8.75), P = 0.449; 2 hour: 6.66 mmol/L (5.85-7.68) vs. 6.75 mmol/L (5.93-7.74), P = 0.142]. The incidence of GDM was no change as the TSH level increased in either TPOAb negative or positive SCH women (all P > 0.05). After using the multivariate logistic regression analysis adjusted for confounders (maternal age, educational levels and preBMI), elevated TSH and TPOAb status also had no effect on the incidence of GDM (Table 1). These results suggested maternal SCH in the first trimester was not related to GDM, regardless of the TPOAb status or the TSH levels.


P. Li: None. S. Lin: None. J. Fan: None.


Science and Technology Planning Project of Guangdong Province (2017A020215026); Medical Scientific Research Foundation of Guangdong Province (A2017314)

Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered. More information is available at