Adverse effects of progestin-primed ovarian stimulation: combination of clinical study and single cell analysis

•PPOS significantly suppressed premature LH surge rates compared with GnRH-ant.•PPOS resulted in significantly lower live birth rates compared with GnRH-ant.•scRNA-seq analysis revealed higher expression of mitochondrial DNA genes in PPOS.•Caution should be exercised when employing the PPOS method.•Combining clinical outcomes with genetic insights improves ART. Does a progestin-primed ovarian stimulation (PPOS) protocol negatively affect reproductive outcomes compared with a GnRH antagonist (GnRH-ant) protocol? This retrospective cohort study included 1,263 patients with normal ovarian reserves undergoing either PPOS or GnRH-ant in their first IVF cycles between 2018 and 2020. An additional genetic analysis included mural granulosa cells (mGCs) from 16 patients between 2021 and 2022. Single-cell RNA sequencing (scRNA-seq) was performed on mGCs of metaphase II (MII) oocyte follicles (eight per protocol). The primary outcomes were the premature luteinising hormone (LH) surge rate for the first inverse probability of treatment weighting (IPTW) analysis and the live birth rate of the first frozen embryo transfer cycle for the second IPTW analysis. The premature LH surge rate was lower in the PPOS than in the GnRH-ant (3.1% vs. 20.1%; OR, 0.13; 95% CI, 0.07–0.23; P < 0.01) in the first analysis. The good-quality cleavage embryo rate was lower in the PPOS group compared with the GnRH-ant group (37.2% vs. 49.1%, P < 0.01). The live birth rate was lower in the PPOS than in the GnRH-ant (31.5% vs. 42.3%; OR, 0.63; 95% CI, 0.46–0.86; P < 0.01) in the second analysis. The scRNA-seq analysis demonstrated higher expression of 12 mitochondrial DNA (mtDNA) genes in the PPOS than in the GnRH-ant. PPOS suppressed the premature LH surge rate but was associated with the lower live birth rate compared with GnRH-ant. The elevated expression of mtDNA genes in mGCs might also indicate a decline in oocyte quality with PPOS. [Display omitted]