Current status of screening and management of thyroid diseases during pregnancy / 中华围产医学杂志

ABSTRACT

Objective To investigate the current status of screening and management of thyroid diseases during pregnancy,and to provide evidence for further improvement of clinical management.Methods Clinical data of 5 981 pregnant women who delivered at Peking University First Hospital between September 1,2013 and September 30,2014 were analyzed retrospectively.Their average age was (30±4) years (18-47 years) and average gestational week was (39.2± 1.6) weeks (25.5-42.0 weeks).The reference range of thyroid stimulating hormone (TSH) was 0.1-2.5 mU/L recommended by the American Thyroid Association (ATA).The reference range of free thyroxine (FT4) was 11.48-22.70 pmol/L and the cut-off value of thyroid peroxidase antibody (TPOAb) was 34 U/ml both recommended by the kit.The specific reference range of TSH was obtained from normal pregnant women in this study (0.23-4.08 mU/L in the first trimester).Pregnant women with hypothyroidism were divided into two groups according to their TSH level at the first trimesterTSH ≥ 2.5-＜4.08 mU/L group and TSH ≥ 4.08 mU/L group.T test,Chi-square or Fisher's exact test were applied for statistical analysis.Results (1) Screening statusOf the 5 981 pregnant women,there were 13 cases (0.2％) of hyperthyroidism and 146 cases (2.4％) of hypothyroidism diagnosed before conception (133 cases of Hashimoto thyroiditis,eight cases after operation for thyroid cancer,and five cases after 131I therapy because of hyperthyroidism).Among the 5 822 cases requiring screening,4 044 cases (69.5％) received screening tests of TSH,FT4 and TPOAb during early pregnancy according to Chinese Guidelines,and 1 778 cases received neither standard screening nor screening test.(2) Treatment of hypothyroidismHypothyroidism treatment rate was only 61.5％ (107/174) according to the reference range recommended by the ATA,lower than that of 88.1％ (52/59) according to the reference range of this study (x2=14.430,P＜0.05).There were 60 cases receiving no treatment in TSH ≥ 2.5-＜4.08 mU/L group.Forty-three of these cases were reexamined,and one of them was abnormal,with a rate of 2.3％ (1/43).There were seven cases without treatment in TSH ≥ 4.08 mU/L group;six of them were reexamined among which one was abnormal,with a rate of 1/6.(3) ThyrotoxicosisAmong the 4 044 pregnant women,99 cases had TSH ＜0.1 mU/L,including 11 cases with FT4 ≥ 22.70 pmol/L (22.82-60.96 pmol/L).Only three cases were positive for thyrotrophin receptor antibody,and then diagnosed as hyperthyroidism and treated with propylthiouracil.(4) Thyroid cancerAmong the 5 981 pregnant women,six cases were diagnosed as thyroid cancer during pregnancy and lactation,with an incidence of 100.3/100 000.Of the six cases,five were diagnosed during pregnancy,and one at one month postpartum.All of the six cases underwent operation and were confirmed to be papillocarcinoma by pathology.Conclusions The screening rate of thyroid diseases during pregnancy is high,but the clinical management is not fully standardized.We suggested that each center should established its own normal reference range for thyroid function test.The incidence of thyroid cancer during pregnancy is increasing,thus attention should be paid to its diagnosis.