1.
Effect of levothyroxine on pregnancy outcomes in women with thyroid autoimmunity: a systematic review with meta-analysis of randomized controlled trials.
Wang, X, Zhang, Y, Tan, H, Bai, Y, Zhou, L, Fang, F, Faramand, A, Chong, W, Hai, Y
Fertility and sterility. 2020;(6):1306-1314
Abstract
OBJECTIVE To investigate whether levothyroxine is associated with improved live birth and other benefits in women with thyroid autoimmunity. DESIGN Systematic review and meta-analysis. SETTING Not applicable. PATIENT(S): Women positive for thyroid peroxidase antibody. INTERVENTION(S): MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials were searched without any language restrictions. Pooled effect sizes were calculated using random-effects models. MAIN OUTCOME MEASURE(S): The primary outcome was the incidence of live birth, miscarriage, preterm birth, clinical pregnancy, ectopic pregnancy, neonatal admission, and birth weight. The summary measures were reported as relative risk (RR) with 95% confidence interval. RESULT(S): Levothyroxine supplementation was not associated with an increased rate of live birth or a decreased risk of miscarriage. Results were similar in subgroup analyses of live birth by age, baseline thyrotropin, baseline thyroid peroxidase antibody, body mass index, and use of assisted conception. For live birth, the effect estimate lay within the futility boundary for RR of 20% and 15%, but at a 10% RR, the effect estimate lay between the futility boundary and the inferior boundary. CONCLUSION(S): High- to moderate-quality evidence demonstrated that the use of levothyroxine was not associated with improvements in clinical pregnancy outcomes among women positive for thyroid peroxidase antibody. REGISTRATION NUMBER PROSPERO CRD42019132976.
2.
The Clinical Value and Variation of Antithyroid Antibodies during Pregnancy.
Li, C, Zhou, J, Huang, Z, Pan, X, Leung, W, Chen, L, Zhang, Y, Wang, L, Sima, Y, Gober, HJ, et al
Disease markers. 2020;:8871951
Abstract
Antithyroid antibodies, which include thyroid-stimulating hormone receptor antibodies (TRAbs), thyroid peroxidase antibodies (TPOAbs), and thyroid globulin antibodies (TgAbs), are widely known for their tight association with thyroid autoimmune diseases. The variation in all three kinds of antibodies also showed different trends during and after pregnancy (Weetman, 2010). This article reviewed the the physiological changes, while focusing on the variation of thyroid antibodies concentration in women during and after pregnancy, and adverse consequences related to their elevation. Since abnormal elevations of these antithyroid antibodies may lead to adverse outcomes in both mothers and fetuses, special attention must be paid to the titer of the antibodies during pregnancy. The molecular mechanisms of the variations in those antibodies have yet to be explained. The frequency and timing of thyroid antibody measurement, as well as different reference levels, also remain to be elucidated.