Efficiency of mild ovarian stimulation with letrozole co-treatment in expected low ovarian responders

Ovarian stimulation (OS) is a critical step in assisted reproductive techniques (ART); it has been routinely adopted since it substantially increases the whole process efficiency. Our study aims to compare the efficiency of mild OS with letrozole co-treatment vs. conventional OS in expected low ovarian responders. A single-centre, observational, comparative, non-experimental and retrospective study using our database at the Reproductive Endocrinology Department at Centro Médico Nacional 20 de Noviembre in Mexico City was performed. We compared the total rFSH dosage per oocyte, we noticed a statistically significant difference between groups, Group A 388.9 vs. Group B 667.2IU per retrieved oocyte (p<0.0002, 105 to 450 IU CI 95%), Comparing total rFSH dosage per follicle, we noticed a statistically significant difference among Group A 397.5 vs. Group B 590.2IU per follicle (p<0.014, 39.2 to 346.2 IU, CI 95%). In expected poor ovarian responders, mild ovarian stimulation with letrozole co-treatment is much more efficient than conventional stimulation.