Abstract: Objective To establish a reference range of thyroid stimulating hormone（TSH） and free thyroxine（FT4） in pregnant women in Hefei. Methods A total of 1 309 women in the normal pregnancy period were collected and divided into three groupsof T1,T2 and T3 depending on their different gestation periods from June 2016 to June 2017. Additionally,150 cases of non-gestation women were selected for pre-pregnancy screening in the hospital as control. Chemiluminescence immunoassay was used for detection of the serum thyroid peroxidase antibody （TPOAb）,TSH,and FT4. Results The reference range of the serum level of TSH was 0.06-5.74mIU/L in the early stage of pregnancy,0.10-5.30mIU/L in the medium term and 0.53-4.67mIU/L in the last term,respectively.The range of FT4values in the early,medium and late periods were 8.29-15.28pmol/L,6.56-11.97pmol/L,and 5.79-10.30pmol/L,respectively. Conclusion The TSH reference range varies in regions and the distinct values should be establishedso as toevaluatethe thyroid function of pregnant women timely and precisely.

Key words: Pregnancy, Thyroid stimulating hormone, ThyroxineReference range