Progestin-primed ovarian stimulation (PPOS) in preimplantation genetic testing for aneuploidy: a retrospective study and meta-analysis

Information on the impact of Progestin-primed ovarian stimulation (PPOS) protocol on embryo euploid status and preimplantation genetic testing for aneuploidy (PGT-A) outcomes is limited compared with other ovarian stimulation protocols. We conducted a retrospective cohort study and a meta-analysis to evaluate the application value of the PPOS protocol in PGT-A cycles.

In the cohort study, we retrospectively analyzed 962 ovarian stimulation cycles, including 413 cycles of PPOS protocol, 327 cycles of gonadotropin-releasing hormone antagonist (GnRH-ant) protocol, and 222 cycles of GnRH agonist (GnRH-a) protocol. In the meta-analysis, we searched PubMed, Embase, Cochrane Library, Web of Science, Sinomed, CNKI, Wanfang and VIP databases as well as clinical trial registration websites. Pooled or narrative analyses were performed on embryo and pregnancy outcomes according to whether baseline characteristics were balanced.

In our retrospective study, compared to the GnRH agonist protocol, patients receiving the PPOS and GnRH antagonist protocols were older, and there was a significant decrease in the number of antral follicles, Anti-Mullerian hormone (AMH) levels, stimulation duration, gonadotropin (Gn) dosage, as well as the number of retrieved oocytes and euploid blastocysts. Regression analysis showed that the ovarian stimulation protocol was not associated with the number of euploid blastocysts or the rate of euploid blastocysts per biopsy. There were no significant differences in the rates of biochemical pregnancy, clinical pregnancy, premature birth, live birth, or miscarriage per embryo transfer among the three groups. The meta-analysis included data from seven studies. There were no significant differences in stimulation duration, Gn dosage, number of oocytes retrieved, number of euploid blastocysts, euploid blastocyst rate, clinical pregnancy rate, or live birth rate between PPOS protocol and GnRH antagonist protocol, but the abortion rate of PPOS protocol decreased significantly.

Current findings indicate that the PPOS protocol is comparable to other ovarian stimulation protocols in embryo euploid status or pregnancy outcomes and may be an attractive option in PGT-A cycles, which needs to be validated in more well-designed RCTs and long-term follow-ups.