The impact of LH-containing gonadotropins on diploidy rates in preimplantation embryos: long protocol stimulation.

BACKGROUND The aim of this study was to evaluate the effect of ovarian stimulation with LH-containing gonadotropins (human menopausal gonadotropin, hMG), on ploidy of human cleavage-stage-embryos. METHODS A total of 104 women, at ages 27-43 years, undergoing one cycle of controlled ovarian hyperstimulation for IVF in combination with preimplantation genetic diagnosis, were eligible for enrollment in this retrospective, controlled cohort study. Ovarian stimulation included down-regulation with long agonist and stimulation with either recombinant FSH or hMG. Since the ploidy of embryos changes with female age, patients were matched for age and dosage of the respective gonadotropin. RESULTS Despite similar numbers of chromosomally normal embryos in both groups, women undergoing hMG stimulation demonstrated significantly higher percentages of diploid embryos than did the FSH-stimulated patients (69.8 versus 45.3%; P < 0.01). CONCLUSIONS Long protocol LH-containing ovarian stimulation improves embryonic ploidy in comparison to pure FSH stimulation. This observation may explain higher IVF pregnancy rates, reported for hMG stimulation in some studies.