Protocol with Progestin-primed Ovarian Stimulation (PPOS) from the Beginning of Stimulation Versus Protocol with GnRH Antagonists for Ovarian Stimulation in Patients Undergoing DUOSTIM with Embryo Accumulation for PGT-A.

Ganirelix is a GnRH antagonist, which modulates the hypothalamic-pituitary-gonadal axis by competitively binding to GnRH receptors in the pituitary gland. Consequently, there is a reversible, intense, and rapid suppression of endogenous gonadotropin release. Ganirelix is indicated for the prevention of premature luteinizing hormone (LH) surges in women undergoing controlled ovarian hyperstimulation (COH) for assisted reproductive techniques (ART).

Medroxyprogesterone acetate is a synthetic progestin (structurally related to progesterone) with antiestrogenic, antiandrogenic, and antigonadotropic action. It inhibits pituitary gonadotropins (FSH and LH) with consequent inhibition of follicular maturation and ovulation . Medroxyprogesterone acetate is active orally and parenterally, 15 times more potent than progesterone. In addition to inhibiting ovulation, progestins also act on the endometrium preventing implantation and increasing the viscosity of cervical mucus, which hinders sperm progression in the uterus. It also transforms a proliferative endometrium into a secretory endometrium, provided that the woman has adequate endogenous estrogen levels.