P-397 The effect of letrozole overlapped with gonadotropin on IVF outcomes in women with DOR or aged over 40 years old

Abstract Study question Evaluating the efficacy of modified letrozole protocol (mLP) for diminished ovarian reserve (DOR) or advanced age women. Summary answer The provides another option women with DOR age, especially those who experienced stimulation previously. What is known already For years, numerous methods have been conducted to obtain better outcomes in DOR. Increasing doses gonadotropin (Gn), exogenous luteinizing hormone (LH) growth factor (GH) supplementation, and various kinds controlled (COS) protocols were reported. However, there still no consensus due contradictory reports comparable reproductive outcomes. During stimulation, estrogen androgen are important recruitment primordial follicles promotion follicular at preantral antral stages across different species. design, size, duration This a paired-match study including 243 249 aged over 40 years old received vitro fertilization (IVF) treatment. Participants/materials, setting, 123 mLP. GnRH agonist (GnRH-a) long, antagonist (GnRH-anta), mild used as controls each group. Clinical pregnancy rate (CPR) cumulative clinical (CCPR) main Main results role chance CPR mLP group (38.46%) was significantly higher than (17.11%), but not from GnRH-a long (26.13%) GnRH-anta (29.17%) CCPR showed an increasing trend (33.33%) although without significance when compared controls. CCRP GnRH-anta, 21.68%, 29.03%, 13.01%, respectively. In repeated cycles, achieved available embryo top-quality rate. Further positive correlation between testosterone number oocytes retrieved (r = 0.395, P< 0.01). Limitations, reasons caution It retrospective which resulted minor bias among other control protocols. Although we paired AMH, presence biases cannot be totally excluded. prospective studies need done validate effect Wider implications findings may effective previous cycle failure. An serum level play reflect during stimulation. Trial registration applicable