Received April 23, 2023
Accepted May 16, 2023

Introduction:To show that the endometrium needs few days of preparation with exogenous oestradiol reach embryo transfer criterions in oocyte donation programmes. Methods:Patient V.M.O.A., 45years old, with primary infertility and present ovarian function, submitted to a second try in oocyte donation program. After pituitary suppression with gonadotrophin releasing hormone analogue (GnRH-a) administrated in the first day of menstrual cycle, it was used the classic scheme for endometrial preparation with estradiol. Results:In the 18th day after GnRH-a administration, the patient presented an important genital bleeding and interrupted the oestradiol administration for two days. The ultrasound detected the presence of two ovarian cysts (18 e 28 mm) and endometrium measuring 2.2mm,type I. In this moment, the oestradiol administration was restarted in a dose of 12mg per day. After this dose utilization during 6 days, a new ultrasound was made and it detected endometrium type II measuring 10mm, when the oestradiol dose was reduced for 8mg per day.A new ultrasound was made three days after that, and it showed a endometrium type II measuring 13mm. This day, 5 donated oocytes were subjected to IVF, which presented 100% of fertilization.The day after, progesterone administration was started by intramuscular way and the oestradiol dose was reduced to 4mg per day. Five embryos were transferred in the second day after insemination, resulting in a single pregnancy with heart beats identified by ultrasound. Conclusion:This case demonstrates clearly that the endometrium can be prepared in a short period of time through higher doses of oestradiol, what facilitates the sincronization between the donater and the receptor during an oocyte donation program.