Impact of Thyroid Autoantibodies on Pregnancy Outcomes in Euthyroid Women: A Prospective Cohort Study

Background Thyroid autoantibodies, including thyroid peroxidase antibodies (TPO-Ab) and thyroglobulin antibodies (TgAb), are commonly found in euthyroid women and have been linked to adverse pregnancy outcomes. However, their role in predicting complications in euthyroid pregnant women remains poorly defined. Objective This study aimed to evaluate the association between elevated TPO-Ab and TgAb levels and the risk of miscarriage, preterm birth, and postpartum thyroiditis in euthyroid women. Methods A prospective cohort study was conducted with 150 euthyroid pregnant women, with blood samples collected in the first trimester to measure TPO-Ab and TgAb levels. Pregnancy outcomes, including miscarriage, preterm birth, and postpartum thyroiditis, were tracked throughout the pregnancy and postpartum periods. Statistical analyses were performed using chi-square tests, logistic regression, and receiver operating characteristic (ROC) curve analysis. Results Elevated TPO-Ab levels were associated with an increased risk of miscarriage (OR=2.5, 95% CI: 1.4-4.2, p=0.003), and elevated TgAb levels were associated with a higher risk of preterm birth (OR=1.8, 95% CI: 1.1-3.1, p=0.028). The incidence of postpartum thyroiditis was significantly higher in women with elevated TPO-Ab levels (50.0% vs. 21.6%, p=0.001). ROC analysis revealed a predictive ability of TPO-Ab for miscarriage (AUC=0.75) and TgAb for preterm birth (AUC=0.70). Conclusion Elevated TPO-Ab and TgAb levels in euthyroid women are associated with an increased risk of adverse pregnancy outcomes, including miscarriage, preterm birth, and postpartum thyroiditis. Screening for thyroid autoantibodies may provide an opportunity for early identification and intervention in high-risk pregnancies.