Problem: Our study aims to investigate whether the anti‐thyroperoxidase antibody (TPO‐Ab) and TSH level in euthyroid women have any association with reproductive outcomes after the ART cycle. Methods of study: A total of 1107 patients who were enrolled in the study were divided into four groups based on serum TSH level and TPO‐Ab status: group A, 0.3 ≤ TSH < 2.5 mIU/L and TPO‐Ab−; group B, 0.3 ≤ TSH < 2.5 mIU/L and TPO‐Ab+; group C, 2.5 ≤ TSH < 4.2 mIU/L, and TPO‐Ab−; and group D, 2.5 ≤ TSH < 4.2 mIU/L, TPO‐Ab+. The differences in ART cycles and pregnancy outcomes were analyzed between study groups. Results: The fertilization rate in group D (73%) was significantly lower than that in groups A (83% P <.001), B (84% P =.001), and C (82% P =.002). The biochemical pregnancy rates of groups B (7%) and D (12%) were significantly higher than those of group A (2%) (P =.028 and P =.017, respectively). TPO‐Ab was related to a higher biochemical pregnancy rate (P =.002, OR = 5.311, 95% CI 1.859‐15.169) and TSH over 2.5 mIU/L was related to higher ICSI rate (P =.001, OR = 1.759, 95% CI 1.250‐2.476) by logistic regression analysis. The receiver operating characteristic (ROC) also verified the results. Conclusion: The impacts of TSH ≥ 2.5 mIU/L on the intracytoplasmic sperm injection (ICSI) rate, TSH ≥ 2.5 mIU/L and TPO‐Ab+ on the fertilization rate, and TPO‐Ab+ on the biochemical pregnancy rate, rather than the effect on abortion, clinical pregnancy, and live birth, were emphasized. [ABSTRACT FROM AUTHOR]