Objective:To analyze the pregnancy outcomes in patients with positive anti-centromere antibodies(ACA)receiving in vitro fertilization(IVF)-embryo transfer(ET)and natural conception.Methods:A case-control study was used to retrospectively analyze the clinical data of 3955 patients who received IVF-ET therapy and had the results of antinuclear antibody(ANA)spectrum at Zhejiang Provincial People's Hospital from June 2016 to June 2023.Patients with positive ACA and negative ACA were matched at a ratio of 1∶3 using propensity score matching.Embryo outcomes of IVF were compared between the two groups,and the impact of different fertilization methods and the use of immunosuppressants on pregnancy outcomes were analyzed using self-matching.The natural conception and disease progress were followed up for ACA-positive patients after IVF failure.Results:The ACA-positive patients accounted for 0.86%of all IVF patients(34/3955)and 2.51%of total ANA-positive IVF patients.Regardless of whether patients received conventional IVF(c-IVF)or intracytoplasmic sperm injection(ICSI),the ACA-positive group exhibited significant differences in oocyte maturity and fertilization compared to the ACA-negative group(both P＜0.01).Moreover,the ACA-positive group had a decreased number of D3 suboptimal embryos and D3 optimal embryos(both P＜0.05).In 5 cases of ACA-positive patients who underwent ICSI cycles,the two pronucleus(2PN)rate did not increase compared to c-IVF cycles(P＞0.05),and there was a decrease in the number of D3 high-quality embryos and D3 suboptimal embryos(both P＜0.05).After 1-2 months of immuno-suppressant treatment,12 ACA-positive patients underwent c-IVF/ICSI again,and there were no changes in egg retrieval and fertilization before and after medication(both P＞0.05),but there was an improvement in the 2PN embryo cleavage rate(P＜0.05).The number of embryos transferred was similar between the ACA-positive and negative groups,but the ACA-positive group had significantly lower embryo implantation rate and clinical pregnancy rate compared to the ACA-negative group(both P＜0.05),with no significant differences in the miscarriage rate between the two groups(P＞0.05).Twenty-seven ACA-positive patients attempted natural conception or artificial insemination after IVF failure,resulting in a total of 7 cases of clinical pregnancy.Conclusions:Serum ACA positivity may disrupt oocyte maturation and normal fertilization processes,with no improvement observed with ICSI and immunosuppressant use.However,ACA-positive patients may still achieve natural pregnancy.