Association of thyroid peroxidase antibody positivity in the first trimester with gestational metabolic disorders: a retrospective study.

Objective: To investigate the association between thyroid peroxidase antibody (TPOAb) positivity in the first trimester and maternal metabolic syndrome in pregnancy.

Methods: The study retrospectively reviewed the medical records for 787 pregnant women. Serum-free thyroid hormone, thyroid stimulating hormone, and TPOAb levels were measured in early pregnancy (<13 weeks gestation). Baseline demographics, clinical characteristics, thyroid function, and pregnancy outcomes were compared between women who were TPOAb positive or TPOAb negative in the first trimester. Associations between TPOAb positivity in the first trimester and the occurrence of gestational diabetes mellitus, hypertensive disorders complicating pregnancy (HDCP), maternal metabolic syndrome in pregnancy, and adverse pregnancy outcomes were explored.

Results: Data for 787 women with a singleton pregnancy were included in the analyses. In women who were TPOAb positive compared to TPOAb negative in the first trimester, baseline HDL-C was significantly lower (1.51 [1.33, 1.81] vs. 1.62 [1.40, 1.87], p = 0.028), and there was a significantly higher incidence of HDCP (15.8% vs. 6%, p < 0.0001), maternal metabolic syndrome in pregnancy (18.8% vs 6.4%, p < 0.0001) or preeclampsia (7% vs, 2.5%, p = 0.024). There was a significant nonlinear association between TPOAb levels in the first trimester and the incidence of HDCP or maternal metabolic syndrome in pregnancy (both p < 0.001). The logit of the probability of having HDCP or maternal metabolic syndrome in pregnancy increased rapidly at TPOAb (log₁₀) ≤ 1.5 (TPOAb (log₁₀) = 1.07 as reference). After adjusting for confounders (maternal age, pre-pregnancy BMI, gravidity, parity and history of adverse events during pregnancy), there was a significantly higher risk of HDCP (odds ratio [OR], 3.029; 95% confidence interval [CI], 1.586, 5.622, p = 0.001), maternal metabolic syndrome in pregnancy (OR, 2.841; 95% CI, 1.473-5.260, p = 0.001), or preeclampsia (OR 3.315, 95% CI 1.305-7.788, p = 0.008) in women who were TPOAb positive compared to TPOAb negative in the first trimester.

Conclusion: TPOAb positivity in the first trimester may increase the risk of HDCP, maternal metabolic syndrome in pregnancy, and preeclampsia, emphasizing the need for universal screening for thyroid disorders and better diagnostic criteria and management strategies for metabolic disorders during pregnancy.