Clinical significance of serum levels of thyroid stimulating hormone receptor antibody in pregnant women with Graves' disease

Objective:To investigate the clinical significance of serum thyroid stimulating hormone(TSH) receptor antibody (TRAb) levels and the antithyroid drug(ATDs) use in pregnant women with Graves’ disease in their neonatal thyroid function. Methods:The serum TRAb and T3,T4,FT3,FT4,TSH levels in 68 pregnant women with Graves’ disease and their newborns were detected by radio receptor assay(RRA) and electrical chemiluminescence immunoassay (ECLIA),respectively.Based on the maternal serum TRAb levels and the use of antithyroid drugs during pregancy, the newborns were divided into different groups.The incidence of neonatal thyroid dysfunction and its risk factors were analyzed. Results:The results showed the incidence of abnormal thyroid function of newborns was 29.4%(20/68).The proportion of neonatal thyroid dysfunction in women with high TRAb levels in the third trimester of pregnancy were significantly higher than these with normal TRAb(P<0.01).In 23 newborns whose mothers were normal in serum TRAb levels and took no ATDs during pregnancy,only one case had thyroid dysfunction within two weeks after birth,while in other 45 newborns whose mothers had a high level of serum TRAb and/or took ATDs during pregnancy, 19 developed thyroid dysfunction within two weeks after birth. Conclusion:Neonatal thyroid function depends on the balance between the transplacental TRAb and ATDs. TRAb measurement in pregnant women with Graves’ disease is of significance in evaluation of neonatal thyroid function. Elevated level of serum TRAb in the third trimester of pregnancy is a risk factor for neonatal thyroid dysfunction.