Yuan Ning, Sun Jianbin, Zhao Xin, Du Jing, Nan Min, Zhang Qiaoling, Zhang Xiaomei
Department of Endocrinology, Peking University International Hospital, Beijing, China.
Endocr Connect. 2022 Apr 22;11(4):e210600. doi: 10.1530/EC-21-0600.
Numerous studies have found that subclinical hypothyroidism (SCH) may increase adverse pregnancy outcomes; however, the benefit of levothyroxine (LT4) treatment remains controversial. The 2017 guidelines of the American Thyroid Association weakly recommended LT4 therapy for serum antithyroid peroxidase antibody (TPOAb)-negative women with thyroid-stimulating hormone (TSH) concentrations greater than the pregnancy-specific reference range and below 10.0 mU/L. Therefore, the primary goal of this study was to investigate the correlation between thyroid autoantibody-negative SCH with or without LT4 treatment and adverse pregnancy outcomes.
We prospectively enrolled 1868 consecutive pregnant women. Finally, 1344 women were involved in the study according to the inclusion and exclusion criteria. Assays for TSH, free thyroxine (FT4), TPOAb, anti-thyroglobulin antibody, and laboratory indicators were performed. The participants were divided into the euthyroid (ET) group (n = 1250) and the SCH group(n = 94). The SCH group was further divided into LT4 group (n = 40) and non-LT4 group(n = 54). The laboratory indicators and pregnancy outcomes were evaluated during follow-ups.
Maternal age, BMI, parity, and the history of spontaneous abortion did not differ significantly between the ET group and the different SCH groups. There were no significant differences in lipid profile and homocysteine levels between ET and SCH group in the first and third trimester of pregnancy. After adjusting the confounding factors, the non-LT4 group was a risk factor for spontaneous abortion (odds ratio: 3.141, 95% CI: 1.060-9.302). Survival analysis showed that the time of abortion was different between the ET group and SCH group (log-rank P= 0.042). The spontaneous abortion in SCH, especially in non-LT4, group mainly occurred in the first trimester of pregnancy.
Thyroid autoantibody negative-SCH seems to be associated with increased risk of spontaneous abortions during the first trimester of pregnancy. LT4 therapy in this patient population might be beneficial to reduce adverse pregnancy outcomes.
大量研究发现亚临床甲状腺功能减退（SCH）可能增加不良妊娠结局；然而，左甲状腺素（LT4）治疗的益处仍存在争议。美国甲状腺协会2017年指南弱推荐对血清抗甲状腺过氧化物酶抗体（TPOAb）阴性、促甲状腺激素（TSH）浓度高于妊娠特异性参考范围且低于10.0 mU/L的女性进行LT4治疗。因此，本研究的主要目的是调查甲状腺自身抗体阴性的SCH无论是否接受LT4治疗与不良妊娠结局之间的相关性。
我们前瞻性纳入了1868例连续的孕妇。最后，根据纳入和排除标准，1344例女性参与了研究。进行了TSH、游离甲状腺素（FT4）、TPOAb、抗甲状腺球蛋白抗体检测以及实验室指标检测。参与者被分为甲功正常（ET）组（n = 1250）和SCH组（n = 94）。SCH组进一步分为LT4组（n = 40）和非LT4组（n = 54）。在随访期间评估实验室指标和妊娠结局。
ET组与不同SCH组之间的产妇年龄、BMI、产次和自然流产史无显著差异。妊娠第一和第三孕期，ET组和SCH组的血脂谱和同型半胱氨酸水平无显著差异。校正混杂因素后，非LT4组是自然流产的危险因素（比值比：3.141，95%置信区间：1.060 - 9.302）。生存分析表明，ET组和SCH组的流产时间不同（对数秩检验P = 0.042）。SCH组，尤其是非LT4组的自然流产主要发生在妊娠第一孕期。
甲状腺自身抗体阴性的SCH似乎与妊娠第一孕期自然流产风险增加有关。该患者群体的LT4治疗可能有助于减少不良妊娠结局。
