Chlormadinone acetate in progestin-primed ovarian stimulation does not negatively affect clinical results.

Purpose: To investigate whether progestin-primed ovarian stimulation (PPOS) with chlormadinone acetate (CMA) adversely affects clinical results and neonatal outcomes, or causes congenital deformities.

Methods: This retrospective study was conducted at private IVF clinic from November 2018 to November 2021. Women underwent oocyte retrieval using gonadotropin-releasing hormone (GnRH) antagonist protocol (n = 835) or PPOS protocol (n = 57) were included. Eligible patients were normal ovarian responders (aged <40, AMH ≧1.0 ng/mL) with freeze-all cycle. Embryo developments, clinical results, or neonatal outcomes of singletons derived from transfer of frozen single blastocysts were compared within each group.

Results: Patient characteristics were similar in both groups. The median LH level (mIU/mL) at trigger in the GnRH antagonist group [2.0 (1.2-3.7)] was significantly higher than in the PPOS group [0.9 (0.3-1.7)]. There was no cycle with premature LH surge in the PPOS group. Fertilization and blastocyst formation rates did not differ significantly between groups. Furthermore, clinical outcomes were also similar in the two groups. Congenital abnormality rates did not differ significantly [0.9% (3/329), 0.0% (0/17)].

Conclusions: CMA using ovarian stimulation did not negatively affect clinical results. Our data suggest that PPOS with CMA is an appropriate ovarian stimulation method for normal ovarian responders.