CONTEXT: Progestins have recently been used as an alternative for gonadotropin-releasing hormone (GnRH) analogues to prevent premature luteinizing hormone surge due to the application of vitrification technology. However, the long-term efficacy and safety of a progestin-primed ovarian stimulation (PPOS) regimen, including oocyte competence, cumulative live birth rate (LBR), and offspring outcomes, remain to be investigated. OBJECTIVE: To compare cumulative LBR of preimplantation genetic testing (PGT) cycles between a PPOS regimen and GnRH analogues. METHODS: This was a retrospective cohort study at a tertiary academic medical center. A total of 967 patients with good prognosis were categorized into 3 groups: 478 patients received a long GnRH agonist, 248 patients received a GnRH antagonist, and 250 received a PPOS regimen. Medroxyprogesterone 17-acetate was the only progestin used in the PPOS regimen. The primary outcome was cumulative LBR. Secondary outcomes included time to live birth, cumulative rates of biochemical and clinical pregnancy and pregnancy loss, and perinatal outcomes. RESULTS: The PPOS regimen was negatively associated with cumulative LBR compared with GnRH antagonists and GnRH agonists (28.4% vs 40.7% and 42.7%). The average time to live birth was significantly shorter with GnRH antagonists than with the PPOS regimen. The cumulative biochemical and clinical pregnancy rates were also lower in the PPOS regimen than GnRH analogues, while cumulative pregnancy loss rates were similar across groups. Furthermore, the number and ratio of good-quality blastocysts were significantly reduced in the PPOS regimen compared with GnRH analogues. In addition, perinatal outcomes were comparable across 3 groups. CONCLUSION: A PPOS regimen may adversely affect cumulative LBR and blastocyst quality in women with good prognosis compared with GnRH analogues in PGT cycles.