P-598 Analysis of the oocyte yield and Ovarian Sensitivity Index with the use of two gonadotropins (FSHr/FSHu) and two pituitary suppression protocols (PPOS/GnRH-ant)

Abstract Study question Is there a difference, in terms of ovarian yield and sensitivity, comparing progestin-primed protocols (PPOS) to GnRH antagonist (GnRH-ant) using different follitropin? Summary answer PPOS is an effective choice, with both follitropis. Nevertheless, could improve sensitivity FSHu increasing the number oocyte without compromising quality. What known already The use new stimulation protocols, starting during luteal phase or randomly shows that endogenous progesterone alone sufficient block LH surge does not compromises competence pregnancy outcomes. For these reasons, exogenous was utilized as innovative model pituitary suppression. Most studies have shown effectiveness compared (antagonist agonist) IVF cycles. donation only three were carried out analyzing effect recombinant FSH (FSHr) design, size, duration It retrospective, cohort, paired study. We analyzed egg cycles Next Fertility Valencia from January 2020 May 2021. In total 93 donors selected eligible, each one undergoing for 186 cycles, 54 received FSHr 39 HP-FSHu. To attempt eliminate possible bias due interpersonal differences, every patient her own control. Participants/materials, setting, methods All underwent two controlled within 6 months, flexible (Ganirelix) other medroxyprogesterone acetate (MPA), monotherapy GnRH-agonist triggering. focusing on: oocytes retrieved, mature (MII) useful (mature morphological alterations). also evaluated Ovarian index (OSI) calculating 1000 IU gonadotropin used Main results role chance Total consumption similar models suppression regardless type FSH. One less control required MPA than GnRH-ant groups. There no premature ovulations used. group difference observed OSI between GnRHa. On hand, statistically significant improvement retrieved (20,2 ± 8,5 vs 23,8 10,9), MII (18,0 7,2 21,2 10,4) (6,4 3,5 7,7 4,6) favor MPA. Also, higher (15,7 6,5 18,6 10,4). No differences detected fertilization blastocyst rate Limitations, reasons caution main limitation lies retrospective nature However, since (Paired study), it gives added value Wider implications findings efficacy efficiency seem be affected by used, this further reassures about possibility patients case fertility preservation PGT-A/M, "DuoStim" Trial registration Not applicable