A clinical study on gestational transient thyrotoxicosis / 中华内科杂志

ABSTRACT

Objective To investigate the prevalence of gestational transient thyrotoxicosis(GTT) and analyze the cause of thyrotoxicosis encountered in this period MethodsAn epidemiologic survey in ten hospitals in Shenyang was performed and 534 pregnant women during the first trimester of pregnancy filled questionaire,received physical examination and had serum thyroid-stimulating hormone(TSH),free T4 (FT4),free T3(FT3),thyroid peroxjdase antibody(TPOAb),thyrotrophin receptor antibody(TRAb),and human chorionic gonadotrophin(hCG)tests.Results(1)The total prevalence of thyrotoxicosis was 9.75%(52/534)in the first trimester and the prevalence of Grrr was 7.86%.which accounted for 80.77%of the thyroxicosis encountered in this period.A total of 88.89%of the overt GTT showed only elevated FT3 level.(2)The level of serum hCG increased gradually in the first trimester.The medians of hCG were 25 300,85 220 and 81 780 IU/L 6,8-10 and 12 weeks after gestation.respectively(P=0.000).The medians of serum TSH were 1.45.1.10 and 0.84 mlU/I,6.8-10 and 12 weeks after gestation,respectively(P＜0.01).(3)When segum hCG was more than 50 000 IU/L,the prevalece of GTT increased obviously.When serum hCG was between 80000 IU/L and 110000 IU/L,subclinical GTT increased significantly.When serum hCG was more than 110000 IU/L,overt GTT increased significantly.Correlation analysis showed that serum hCG was related negatively with TSH(r=-0.402,P=0.000)and positively with FT3(r=0.165,P=0.000),but not related with FT4.Conclusions The prevalence of GTT is 7.86%in the first trimester and it is the main cause of thyrotoxicosis found in the first trimester,accounting for 80.77%of all the causes.The serological characteristic of overt GTT is mainly the elevation of serum FT3 leveL Serum hCG level is related with the severity of GTT.