Maternal thyrotoxicosis in the first trimester: a clinical analysis of 150 cases

Clinical data of 150 pregnant women, who were confirmed with maternal thyrotoxicosis during January 2010 to January 2014, including 104 cases of gestational transient thyrotoxicosis (GTT)and 46 cases of Graves disease (GD), were retrospectively analyzed; 65 normal pregnant women served as controls. Patients with GD had lower body mass index (BMI) than those with GTT and normal controls [(18±5), (20±4)and (22±4) kg/m2, respectively, P<0.05]. The frequency of thyrotoxic history and hyperthyroidism symptoms in GD patients were significantly higher than that in GTT patients [33%(15/46) vs. 3%(3/104) and 52%(24/46) vs. 15%(16/104), respectively, both P<0.01]. In the first trimester, patients with GD presented lower TSH levels than those with GTT and controls(M=0.021, 0.045 and 1.660 mU/L, respectively, P<0.05)and higher free T4 (FT4) (M=24.99 vs.19.99 pmol/L, P<0.05), free T3 (FT3) (7.10 vs. 5.85 pmol/L, P<0.05), thyroid peroxidase antibody (TPOAb) (99.22 vs. 4.54 kU/L, P<0.05) and thyrotrophin receptor antibody(TRAb) (5.28 vs. 0.11 U/L, P<0.05) levels than patients with GTT. In the second trimester, there were 67%(70/104) GTT patientsand 4%(2/46) GD patients had normal TSH; and FT4 returned to normal in 82%(85/104) GTT patientsand 17%(8/46) GD patients. In the third trimester, there were 100% (104/104) GTT patients and 9% (4/46) GD patients had normal TSH; and FT4 returned to normal in 100% (104/104) GTT patients and 48% (22/46) GD patients. Key words: Thyrotoxicosis, pregnant women; Graves disease