The normal reference range of thyroid function in different periods of pregnant women in Lanzhou,Gansu Province

Objective To observe the range of normal reference values of thyroid function and its dynamics among normal pregnant women in different periods.Methods A cross-sectional study was conducted from December 1 st, 2017 to November 30 th, 2018. Pregnant women who underwent first routine care were screened and 649 cases were recruited. Questionnaire survey was used to collect basic information from pregnant women. All the subjects tested thyroid stimulating hormone(TSH), free tetraiodothyronine(FT₄), free triiodothyronine(FT₃), thyroid peroxidase(TPO) antibody and thyroglobulin(TG) antibody values.Results The normal values of TSH was(0.409-4.284) uIU/mL,(0.898-4.514) uIU/mL, and(1.252-4.526) uIU/mL, and that of FT4 was(8.851-18.060) pmol/mL,(8.406-17.391) pmol/mL, and(8.402-17.922) pmol/mL, and that of FT3 was(1.587-4.418) pg/mL,(1.895-4.612) pg/mL and(2.205-4.812) pg/mL, respectively, among 649 pregnant women during early, middle, and late pregnancy.Conclusion This study provides evidence for establishing the normal reference ranges of serum TSH, FT₄ and FT₃ among women during specific periods of pregnancy at Lanzhou. It is meaningful to ensure risk management of pregnant women, reduction of disease burden and early prevention of adverse fetal outcomes.