Prematurely condensed chromosomes and meiotic abnormalities in unfertilized human oocytes after ovarian stimulation with and without gonadotropin-releasing hormone agonist

Objective: To investigate the incidence of meiotic abnormalities, aneuploidy, and prematurely condensed sperm chromosomes in failed fertilized oocytes after controlled ovarian hyperstimulation (COH). Design: Retrospective analysis of air-dried preparations of unfertilized oocytes. Setting: University hospital-based infertility clinic. Patient(s): Thirty-three patients undergoing IVF having only tubal factor as the cause of infertility. Twelve patients (13 cycles) underwent treatment with hMG alone (-GnRH agonist [GnRH-a]), and 21 patients (24 cycles) underwent treatment with leuprolide acetate (LA) and hMG (+GnRH-a group). Intervention(s): Standard IVF-ET treatment cycle for ovarian stimulation using hMG with or without LA. Main Outcome Measure(s): The meiotic stage, ploidy, and the presence of prematurely condensed sperm chromosomes were determined in 161 air-dried preparations of unfertilized oocytes. Result(s): Significantly more unfertilized oocytes were at metaphase II in the -GnRH-a group as compared with the +GnRH-a group, with significantly fewer exhibiting meiotic aberrations. Aneuploidy rates did not differ between groups. However, significantly more oocytes in the +GnRH-a group revealed prematurely condensed sperm chromosomes than in the -GnRH-a group. Conclusion(s): The use of GnRH-a for COH does not have an impact on aneuploidy rates in failed fertilized oocytes. However, the higher incidence of meiotic aberrations and prematurely condensed sperm chromosomes in the unfertilized population indicates that some retrieved oocytes exhibit incomplete nuclear and cytoplasmic maturation after the use of this agonist. (C) 1997 by American Society for Reproductive Medicine.