Gestational Age-specific Reference Intervals For Maternal Thyroid Function In Shijiazhuang

Background: By the influence of the various hormones during pregnancy, the level of thyroid hormones in pregnant women is quite different from the non-pregnant women, and also there are significant differences in different trimester of pregnancy. Detection method, reagent, sample size, the iodine nutrition and other factors contribute to the differences of gestational age-specific reference intervals for maternal thyroid function, which is established in different countries and regions. The normal reference intervals for maternal thyroid function that is recommended by The American Thyroid Association(ATA) differs from that of Chinese pregnant women. Thus, setting up the gestational age-specific reference intervals for maternal thyroid function of different region is helpful to clinical diagnosis, treatment and monitoring of pregnant women with thyroid disease, reducing the missed diagnosis and misdiagnosis of thyroid disease, especially hypothyroidism and subclinical hypothyroidism, avoiding inappropriate treatment.Objective: To establish the gestational month-specific stage(first trimester of pregnancy Tl, second trimester of pregnancy T2, the third trimester of pregnancy T3) reference intervals for maternal thyroid function in the area of Shi Jia Zhuang, which provides reference for screening, diagnosing, treating thyroid disease during pregnancy.Methods: According to the National Academy of Clinical Biochemistry(NACB) guidelines, subjects(N=120)were selected from pregnant women who took routine examinations during the pregnancy in The Fourth Hospital of Hebei Medical University from June 2013 to November 2014.We selected 60 normal non-pregnant women who accepted physical examination in The Fourth Hospital of Hebei Medical University physical examination center and some volunteers as control group. The study was used to establish reference intervals for maternal thyroid function, that is, the thyroid hormone levels of the first, second, third trimester of pregnancy was from the same pregnant woman. At the first trimester of pregnancy, we measured serum FT3, FT4, TSH, TPOAb, TGAb. If they matched the NACB recommend conditions,we measured serum FT3,FT4,TSH at the second and the third trimester of pregnancy. Using 95% reference range to establish pregnancy specific serum FT3, FT4, TSH normal reference intervals.Results:1 Normal non-pregnant women’s serum FT3 median and the 95% reference ranges was 5.05(4.25-6.80)pmol/L, and serum FT4 median and the 95% reference ranges was 14.55(10.57-17.07)pmol/L, and serum TSH median and the 95% reference ranges was 2.08(0.44-5.34)u IU/ml.2 FT3 median and the 95% reference ranges in the first, second, third trimester of pregnancy was 4.85(3.90-6.64)pmol/L, 4.25(3.47-6.56)pmol/L, women with thyroid disease. 4.13(3.50-5.10)pmol/L。3 FT4 median and the 95% reference ranges in the first, second, third trimester of pregnancy was 15.12(12.04-24.06)pmol/L, 13.53(8.46-24.98)pmol/L, 11.86(7.31-15.13)pmol/L.4 TSH median and the 95% reference ranges in the first, second, third trimester of pregnancy was 1. 28(0.10-4.62)u IU/ml, 1.76(0.29-4.86)u IU/ml, 2.06(0.26-5.21)u IU/ml.Conclusion:1 We established gestational age-specific reference intervals for thyroid function in Shi Jia Zhuang area.2 Reference intervals for thyroid function was quite different between pregnant women and non-pregnant women.3 Reference intervals for maternal thyroid function was quite different in different trimesters of pregnancy, establishing trimester-specific reference intervals of serum FT3, FT4, TSH for normal pregnant women would be helpful to accuracy screening,clinical diagnosis and treatment of pregnant...