Free Thyroxin T4 in Early Pregnancy and Risk of Gestational Diabetes Mellitus

Abstract

Our study aims to evaluate the correlations between thyroid hormone levels in early pregnancy and the incidence of gestational diabetes mellitus (GDM). A total of 2112 pregnant women were recruited from our hospital, Guangzhou, China, from June 2016 to June 2017. Fasting plasma glucose (FPG), Thyrotropin (TSH), free T4 (FT4), and thyroid peroxydase antibody (TPO-Ab) were measured at 9-14 weeks’ gestation (first trimester) and 75-g OGTT (24-28 weeks’ gestation) were performed in each subject. Diagnosis of GDM was made by the IADPSG guideline (2010). All subjects had median age of 30 years (interquartile range:27-34 years). Two hundred and twenty four subjects (10.6%) were diagnosed as GDM. GDM women had older age and higher FPG(P<0.05). The level of free T4 (FT4) in GDM women was similar than that in non-GDM women (16.45±3.42pmol/L and 16.80±3.46 pmol/L, respectively, P=0.152). No difference was observed in the levels of TSH and TPO-Ab between GDM women and non-GDM women (all P>0.05). The prevalence of GDM in subjects among different quartiles of FT4 levels were 11.9%, 11.5%, 9.5% and 9.5% from the first to fourth quartile (P=0.429,χ2=2.766). By using logistic regression, FT4 in the first trimester odds ratios for GDM were not significant: OR 0.970 [95% CI 0.931-1.011] (unadjusted) and 0.960[95% CI 0.920-1.002] (adjusted for age, TSH, TPO-Ab). Our results indicated the level of FT4 in the first trimester may not have strong correlation with incidence of GDM. Disclosure P. Li: None. S. Lin: None. L. Li: None. L. Ouyang: None. J. Fan: None.