Dexeus Mujer has conducted a prospective study to evaluate whether starting ovarian stimulation in the luteal phase (LS) or the follicular phase (FS) of the menstrual cycle offers better reproductive outcomes. The study was conducted in 44 oocyte donors who underwent two cycles of ovarian stimulation consecutively: one started in the luteal phase and the other in the follicular phase. The aim of the researchers was to test whether luteal phase start (LS) and follicular phase start (FS) in the same patient offered a similar number of healthy embryos after inseminating the oocytes obtained with the same sperm sample. The results showed that the number of euploid embryos that reached the blastocyst stage was similar, regardless of whether the oocytes inseminated were from the LS or FS cycle.
Comparison of blastocyst euploidy rates following luteal vs. follicular phase stimulation in a GnRH antagonist protocol. A prospective study with repeated ovarian stimulation cycles
Francisca Martinez, Elisabet Clua, Marta Roca, Sandra Garcia, Nikolaos P Polyzos.
Hum Reprod. 2022 Oct 21;deac222. doi: 10.1093/humrep/deac222.