Introduction: So far, most studies have evaluated the effect of each endometrial preparation cycle alone on patients, and limited studies have comparatively evaluated the results of the cycles with each other. Therefore, in this study, we have evaluated the comparison of endometrial preparation cycles with each other.

Materials and Methods: This retrospective descriptive study was conducted in Mahdieh Hospitals, Tehran, from 2021 to 2023. The study population included endometriosis patients who were candidates for endometrial preparation cycles (GnRH, estradiol, letrozole). The required information of women, including age, history of underlying diseases, type of infertility, duration of infertility, maternal gestation, history of premature birth, and other required information were extracted from the patient records and entered into a predetermined checklist. After selecting the patients, the patients were divided into three groups. One group was GNRH agonists followed by estrogen and progesterone, the second group was estrogen and progesterone, and the third group was letrozole and gonadotropin.

Results: The results showed that the mean anti-Mullerian hormone in the estradiol group was higher than the other two groups, which was statistically significant (p=0.02). The number of embryos transferred in the letrozole group was significantly higher than the other two groups (p=0.04). In contrast, the number of transfers in the GnRH group was higher than the other twos average, which was not significant (p<0.05).