Establishment Of Reference Range For Specific Thyroid Function During Pregnancy And Analysis Of Influencing Factors Of Hypothyroxinemia

Objective:To establish a reference range for s thyroid function during pregnancy and to explore the influencing factors of hypothyroxinemia?low T4?during pregnancy.Methods:A retrospective analysis of 2996 cases of thyroid function in pregnant women with single pregnancy without thyroid disease and family history.Results:?1?Establish a unified reference range for specific thyroid function during pregnancy,early?middle and late trimesters TSH were 0.024⁶.39,0.16⁶.23,0.64⁶.59 mU/L respectively,and FT4 were 11.32²3.00,9.39¹8.92,8.54¹6.73 pmol/L respectively;further establish the specific reference range of the two different age group pregnant women separately,There was no difference in the detection rates of various thyroid diseases when using their respective reference ranges and the unified reference range of the hospital?P>0.05?;?2?The detection rate of various thyroid diseases?except Subclinical hyperthyroidism?of our subject with a reference rangeguide was significantly higher than the reference range with the hospital?P<0.05?.?3?Changes of thyroid-related indicators with pregnancy:TSH levels in the third trimester were significantly higher than those in the first trimester and the second trimester?P<0.05?.There was no significant difference between the first trimester and the second trimester?P>0.05?.The FT4 levels gradually decreased during pregnancy?P<0.05?;the positive rate of TPOAb was significantly higher in the first trimester and the second trimester than in the third trimester?P<0.05?.There was no significant difference between the first trimester and the second trimester.>0.05);the positive rate of TGAb decreased gradually with pregnancy?P<0.05?.?4?The detection rates of hypothyroxinemia in all pregnant women with FT4 cut points of P_2.5.5 and P₅ were 4.6 and 7.4%,respectively.?5?Comparing the mean age,gestational age,UIM and thyroid antibody positive rate between the hypothyroxinemia group and the control group,only the mean age and gestational age were different?P<0.05?;Logistic binary regression analysis of factors,age was the risk factor for hypothyroxinemia during pregnancy?P<0.05?.Conclusions:?1?Different age group both can use the thyroid reference range of our hospital during pregnancy.The establishment of thyroid reference range can avoid over-diagnosis of thyroid disease during pregnancy.?2?Age is a possible influencing factor of hypothyroxinemia during pregnancy.