Received February 21, 2022
Accepted September 26, 2022

Objective: several strategies have been proposed for ovarian stimulation like using an increased daily dose of gonadotropins (300–450 IU per day) with GnRH agonist (long, stop or micro dose flare protocols) or using GnRH antagonist protocols the objective of this study is comparison of the efficacy of flexible GnRH antagonist protocol and GnRH agonist flare protocol for ovarian stimulation in women above 40 years old undergoing IVF. Methods: the study was performed between January 2016 and February 2019. One hundred and fourteen women aged between 40 and 42 years underwent IVF were divided into two groups; group I who were treated by Flexible GnRH antagonist protocol (Antagonist group, n= 68) and group II who were treated by Flare GnRH agonist protocol (Flare group, n= 46). Results: patients treated with antagonist protocol showed a significantly lower cancellation rate, compared with patients treated with flare agonist protocol (10.3% vs. 21.7%, P value 0.049). The other parameters evaluated did not show statistically significant differences. Conclusions: our finding showed that both Flexible antagonist and Flare agonist protocols had comparable outcomes with lower cycle cancellation rate for older patients treated with antagonist protocol. Our findings demonstrated that the antagonist protocol in older women might be detrimental.