A new study surprisingly finds that many women who successfully became pregnant after proceeding with a donor egg cycle, never use their remaining frozen embryos again:

Published last month in the journal Fertility and Sterility, the study looked at 829 women who underwent IVF using donor embryos at the New York University Fertility Clinic between January 2000 and December 2004. Researchers found that more than half — 54 percent — of the women had a baby, or multiples, after that 40 percent of those women elected to freeze and store any extra embryos that were not implanted. However, by August 2009, only 21percent of the women who had their embryos stored actually returned to the clinic to try for a second pregnancy using the stored embryos. For women whose initial attempt at IVF failed and had their extra embryos frozen, 87 percent returned for a second attempt.

According to Reuters, the research team, led by Jaime M. Knopman, M.D., concluded the findings suggest that most women conceive using donor eggs “are satisfied after experiencing only one successful outcome,” and added that many women who give birth to multiples may be especially likely to feel this way; out of 81 participants who had twins after their first attempt, 74 did not return to use their extra embryos.

The NYU fertility clinic offers patients the option of using either an “exclusive” or shared anonymous egg donor. With the shared donor, two women can receive eggs from one donor, as long as there are at least 12 eggs available. Knopman’s team suggested that since the number of women who want donor eggs is growing, and the number of donors is limited, fertility centers should considered a shared donor program, which they suggest “will maximize efficiency, reduce costs, and achieve fertility for a larger number of infertile patients,” and “would markedly reduce the number of unused frozen embryos.”

If nothing else, this study should encourage physicians to discuss the benefits of a shared donor program with their patients. By proceeding with a shared donor cycle, patients can not only significantly reduce the cost of IVF, but avoid having to make the difficult decision about what to do with their excess embryos.