If I use an egg donor, how many embryo transfers can I expect?
PFC maintains detailed records of all treatment procedures and outcomes at our world class laboratory. Nevertheless, the answer to this question is not as straight forward as one might expect. Averages can be summarized, but there are wide swings in the first stage of this procedure - how many eggs a donor can produce. Also, the decision on how many fertilized eggs to implant and how many to freeze can be highly subjective according to the patient.
In 2002, each donor recipient received an average of 23 eggs. But one donor that year failed to produce even a single egg, whereas another donor produced a remarkable 52 eggs. Several successful pregnancies resulted from only a three egg retrieval, so remember, it only takes one healthy embryo to establish a pregnancy!
Once the eggs are retrieved, the fertilization rates are a tad bit more predictable, since most of the donors are in their 20s. In 2002, between 65% - 76% of the retrieved eggs from donors successfully fertilized, depending on whether the donated eggs underwent IVF or IVF-ICSI.
In the next step, the implantation stage, PFC transferred on average 2.3 embryos per patient, and froze on average 7.8 from a single donor cycle. (The average number for freezing would have jumped from 7.8 to nearly 10 if this figure had excluded the 20% of women who did not produce enough eggs for freezing.)
In other words, 80% of donor egg recipients had at least some remaining embryos to freeze after the initial implantation.
And the odds were good for those embryos that entered the deep freeze. Last year, 77% of all thawed embryos were transferred, an improvement over previous years.