Maternal thyroid-stimulating hormone level and thyroid peroxidase antibody status in the first and second trimester of pregnancy and their relationship with the risk of gestational diabetes mellitus

Abstract

Objective:To investigate thyroid-stimulating hormone (TSH) levels and thyroid peroxidase antibody (TPOAb) in early pregnancy and to estimate the risk of development of gestational diabetes mellitus (GDM).Methods:The levels of TSH, free thyroxine, free triiodothyronine, and TPOAb were retrospectively evaluated in 2333 pregnant women. All women recruited were divided into groups of TSH high (H), TSH low (L), TSH (H) TPOAb positive (+), TSH (H)TPOAb negative (-), TSH normal (N)TPOAb (+), TSH (L)TPOAb (+), TSH (L)TPOAb (-), and estimated the risk of GDM.Results:TSH level (X2= 13.0024, P = 0.0015) and TSH combined TPOAb (X2= 20.0038, P = 0.0012) were correlated to development of GDM. The level of TSH in 95 women was increased, and in 216 women were decreased. Of the 2333 pregnant women, 546 patients were diagnosed with GDM, with a prevalence of 23.40%. The prevalence of GDM was 35.78% and 28.70% for the TSH high (H) and TSH low (L) pregnant women, respectively. The increased TSH (P = 0.0013, odds ratio: 2.09, confidence interval:1.34-3.28) was correlated to increase GDM incidence. TSH (H) TPOAb (+) (n = 29), TSH (H) TPOAb (-) (n = 58), TSH normal (N) TPOAb (+) (n = 265), TSH (L) TPOAb (+) (n = 30), TSH (L) TPOAb (-) (n = 154) were in this study. The prevalence of GDM was 51.72%, 29.31%, 23.02%, 26.67%, and 29.87% for the TSH (H) TPOAb (+), TSH (H) TPOAb (-), TSH (N) TPOAb (+), TSH (L) TPOAb (+), and TSH (L) TPOAb (-) pregnant women, respectively. Only the TSH (H) TPOAb (+) pregnant women had a significant higher incidence of GDM (P = 0.0018, odds ratio: 3.63, confidence interval: 1.62-8.16). Trimester specific results showed that only second trimester had higher GDM risk either analyze TSH or the combination of TSH and TPOAb.Conclusion:Elevated TSH level and TPOAb positive in the second trimester of pregnancy were correlated to an increased risk of GDM.