Objective To determine whether color doppler ultrasonography (CDU),thyroid function or thyroid autoimmune antibodies could identify Graves' disease in pregnancy(GDP) in pregnant patients with newly diagnosed thyrotoxicosis.Methods It is an observational study.Sixty-eight pregnant patients with newly diagnosed thyrotoxicosis including gestational hyperthyroidism (GHT) subjects (GHT group,n =33) and GDP subjects (GDP group,n =35),and 62 age-and sex-matched healthy subjects (C1 group:pregnant,n =32,C2 group:non-pregnant,n =30) were recruited.Thyroid function,human chorionic gonadotropin(HCG),thyroid autoimmune antibodies were detected.Peak systolic velocity of the superior thyroid artery (STA-PSV) and diastole inner diameter(STA-D) of the superior thyroid artery were measured by CDU.A ROC curve was used to evaluate STA-PSV,STA-D,thyroid function and thyroid autoimmune antibodies for identification of GDP.Results The area under the ROC curve of STA-PSV,STA-D and thyroid stimulating hormone (TSH),free T4 (FT4) for GDP were 0.905,0.887,0.803 and 0.786,respectively.The optimal cut-off points of STA-PSV,STA-D,TSH and FT4 for GDP were 40 cm/s,2.0mm,0.03 mIU/L and 30 pmol/L with the sensitivity of 82.9％,72.1％,81.8％,76.2％ and specificity of 81.8％,87.9％,75.2％,80.3％,respectively.Conclusions Detection of STA-PSV and STA-D by CDU,as well as thyroid function,is useful in screening GDP in pregnant patients with thyrotoxicosis.

~(131)I uptake by thyroid were assayed in 64 patients with Graves′ disease (GD) and 69 patients with non-GD hyperthyroidism. GD group had higher rate of ~(131)I uptake than non-GD group at 2, 6 and 24 h, and there was no overlap between the two groups at these 3 time points.~(131)I uptake at 2 and 6 h could differentiate GD fromlow ~(131)I uptakehyperthyroidism.