Live babies born per oocyte retrieved in a subpopulation of oocyte donors with repetitive reproductive success

Objective: To investigate the oocyte-to-baby rate when controlled ovarian stimulation was performed on a highly successful donor population and to evaluate whether they produce a higher proportion of reproductively competent oocytes compared with standard donors.

Design: Retrospective analysis of clinical and embryological database.

Setting: University center.

Patient(s): A total of 191 oocyte donation cycles were analyzed from 53 donors (28 best-prognosis donors and 23 standard donors).

Intervention(s): None.

Main outcome measure(s): Total number of oocytes collected, the number of embryos transferable (fresh and frozen). and corresponding oocyte to live baby born (LBB) rates. In patients with remaining frozen embryos, the final LBB rate was estimated according to our reported rates.

Result(s): A total of 130 oocyte retrievals from the best-prognosis donors yielded 2,470 oocytes. The total LBB per oocyte retrieved and LBB per embryo transferred was 7.3% and 24.6%, respectively. A total of 61 oocyte retrievals from the standard donors yielded 1,044 oocytes. The total LBB per oocyte and LBB per embryo transferred was 5.0% and 16.6%, respectively. This is significantly different from the best-prognosis donor group. Success rates were also analyzed after grouping donors based on the number of oocytes retrieved per cycle. In the best-prognosis group, the oocyte use rate increased significantly when fewer oocytes were retrieved, whereas the oocyte-to-baby rate was similar regardless of the number of oocytes for the standard donor group.

Conclusion(s): This retrospective analysis revealed the existence of a subset of good-prognosis donors who produce a higher oocyte-to-baby rate that is indicative of a more biologically efficient reproductive system. Their identification, albeit a posteriori, has clinical implications for safety, by reducing ovarian hyperstimulation syndrome and multiple pregnancies, as well as for assisted reproductive technology success.