Objective: To compare the results of ovarian stimulation with LH surge blockade by medroxyprogesterone acetate or GnRH antagonist in oocytes donors. To present current options of exogenous and endogenous progestins instead of GnRH analogues to block LH surge during ovarian stimulation.
Design: Retrospective study of oocyte donor cycles and literature review.
Setting: Department of Obstetrics and Gynecology, Faculty of Medicine, Masaryk university and University Hospital Brno.
Methods: Thirteen oocyte donors (26.8 ± 2.5 years old) were stimulated with recFSH and MPA to block the LH surge during January - October 2017. The results were compared to the previous cycle stimulated with recFSH and GnRH antagonist performed during January -December 2016. Wilcoxon´s pair test was used to test the statistics. A literature search of SCOPUS was carried out.
Results: In cycles with MPA blockade the average number of oocytes was 14.5 ± 5.1, in cycles with GnRH anta-gonist blockade 12.0 ± 4.5 oocytes (statistical significance p = 0.025). FSH total dose (1611 ± 327 vs. 1565 ± 322 IU), days of stimulation (9.1 ± 0.8 vs. 8.5 ± 0.9) and maximum estradiol levels (5.9 ± 2.1 vs. 6.0 ± 3.0 nmol/l) were not statistically different. Progestins are effective in blocking the LH surge during ovarian stimulation and do not affect the number and quality of collected oocytes or obtained embryos. Their adverse effect on the endometrial receptivity obstructs the embryo implantation in the same cycle. Such protocol requires total freezing and delayed transfer. Progestins can be used in a variety of stimulation protocols - progestin primed follicular phase stimulation, luteal phase stimulation with endogenous progesteron, double stimulation in follicular and luteal phase of the same cycle "duostim" in low responders.
Conclusion: Eggs donor ovarian stimulation with MPA resulted in more oocytes than stimulation protocol with GnRH antagonist, the total dose of FSH and the length of stimulation were similar. According to current experiences progestins effectively block the LH surge and do not affect the number and quality of collected eggs and obtained embryos. Their use opens new possibilities of ovarian stimulation protocols and their flexibility. Its main constraint is that it requires total freezing and delayed transfer.
Keywords: LH block luteal phase stimulation.; medroxyprogesterone acetate; oocyte donation; ovarian stimulation; progestins.