OBJECTIVE:

Euploid blastocyst rate comparison between ovarian stimulation in follicular vs luteal phase performed in the same menstrual cycle in patients with poor ovarian response.

MATERIALS AND METHODS:

Clinical, prospective and comparative study conducted at Centro de Reproducción Arcos S.C., “Nascere”, during january-july, 2019. Patients with PGT-A indication and poor ovarian response according to Bologna criteria were included. Under a short GnRH-antagonist protocol, stimulations, both in follicular and luteal phase were performed using rFSH/rLH (2:1) from day 3 of the cycle and 5 days after the first oocyte retrieval. In addition, ovulation trigger with an GnRH agonist was used, finally, on day 5-6 of embryo development, trophoctoctoderm biopsy was performed.

RESULTS:

In this study, 20 patients were included; when comparing follicular phase vs luteal phase, we found that fertilization rate was 79% (95%CI 29-46) vs 55% (95%CI 34-53), blastocysts rate was 42% (95%CI 19-44) vs 45% (95%CI 24-55) and euploid embryo rate was 100% (95%CI 44-53) vs 70% (95%CI 38-46). Only the oocyte recovery rate in metaphase II showed significant differences between both phases 40% (IC 95% 18-37) vs 59% (IC 95% 31-59), p=0.0333.

CONCLUSION:

Biphasic ovarian stimulation (follicular/ luteal) in the same menstrual cycle (DuoStim) resulted in a higher metaphase II ooctye recovery rate during the luteal phase in comparison with the follicular phase. However, the rates of blastocysts and euploid blastocysts were similar between both phases.