Prognostic factors in oocyte donation: an analyses through egg-sharing recipient pairs showing a discordant outcome

Objective: To analyze prognostic factors that are associated with a discordant outcome in egg recipients sharing oocytes from the same donor. Design: Matched case-control single-center study. Setting: Private infertility clinic. Patient(S): Four hundred forty-four recipients (222 pairs) sharing oocytes from the same donor and showing a discordant outcome. Intervention(s): Controlled ovarian hyperstimulation of egg donors, oocyte donation, intracytoplasmic sperm injection, and ET in egg recipients. Main Outcome Measure(s): Recipient age, obstetric (gravidity, parity) and gynecologic variables (previous uterine surgery, uterine fibroids, uterine malformations, endometriosis, history of tubal infertility), previous oocyte donation cycles, duration of E-2 replacement, received cumulus-oocyte complexes, mature (MII) oocytes, fertilized oocytes, transferred embryos, mean embryo score, transfer difficulty, and semen parameters. Result(s): No significant differences were found in the above-mentioned prognostic factors between the study and control groups. Conclusion(s): Recipient- and cycle-related prognostic factors investigated in our study were not associated with a discordant outcome in recipient pairs sharing oocytes from the same donor, Other possible prognostic factors involving oocyte donor heterogeneity, embryo aneuploidy rates, male factor infertility, and endometrial receptivity should be further investigated. (Fertil Steril((R)) 2007;88:1548-53. (c) 2007 by American Society for Reproductive Medicine.)