Received October 28, 2025
Accepted November 09, 2025

Objective The aim of this study was to investigate whether there were differences in the number of good-quality blastocysts after 6 days of treatment with r-hFSH followed by late follicular phase treatment with r-hFSH:r-hLH in a 2:1 fixed ratio combination or HP-hMG in a PPOS protocol in a population of young women. Methods Healthy oocyte donors were randomized to Group 1 or Group 2 (40 women per group). All donors were treated with 200 mg/day oral progesterone from Day 1 and 225 IU/day r-hFSH for the first six days of ovarian stimulation. From Day 7 onwards, Group 1 received 225 IU/day r-hFHS:r-hLH 2:1 fixed ratio combination and Group 2 received 225 IU/day HP-hMG. Insemination was performed using intracytoplasmic sperm injection. Embryo quality was graded using the SART classification. The primary outcome was the number of blastocysts with good morphology (AA or AB). Results The mean (SD) number of good-quality blastocysts was significantly higher in Group 1 compared with Group 2 (3.4 [2.0] vs. 2.3 [2.0]; difference 0.9 (0.6 to 1.7); Kruskal-Wallis test p=0.0359). There was no difference in total gonadotropin dose, length of stimulation or number of oocytes retrieved between the groups. Conclusion Treatment with r-hFSH:r-hLH in a 2:1 fixed ratio combination starting in the late follicular phase resulted in a significantly higher number of good-quality blastocysts compared with HP-hMG in oocyte donors receiving PPOS.