Objective To determine the correlation between low anti-nuclear antibody（ANA） titers and pregnancy outcomes after frozen embryo transfer（FET）. Methods Clinical data were collected from 1 562 patients undergoing FET at the Reproductive Center of the Affiliated Hospital of Shandong University of Traditional Chinese Medicine between January 2019 and January 2022. The patients were initially divided into the low-titer ANA-positive group（n=155） and ANA-negative group（n=1 407） based on their ANA test results. After propensity score matching，there were 48 patients each in the ANA-positive and ANA-negative groups. The pregnancy outcomes of the two groups were retrospectively analyzed. Results Patients in the ANA-positive group were older than those in the ANA-negative group（P=0.027），with significantly lower clinical pregnancy rate（P=0.008） and live birth rate（P=0.012）. There were no significant differences in ectopic pregnancy rate，miscarriage rate，premature birth rate，single premature birth rate，single birth weight，and single birth length between the two groups（P>0.05）. Low-titer ANA positivity was an independent influencing factor for clinical pregnancy（P=0.008） and live birth（P=0.014） after FET. Clinical pregnancy（OR=0.325，95%CI=0.140-0.750） and live birth（OR=0.342，95%CI=0.146-0.801） after FET were more difficult for patients with low-titer ANAs compared to those without ANAs. Conclusion Low ANA titers are associated with FET pregnancy outcomes and have adverse effects on clinical pregnancy and live birth.