Q: What is the typical time frame for shipment of donor oocytes once a donor is selected?A: If you are selecting frozen eggs in the egg bank, shipment may be immediate. If you select a donor that does not have banked eggs, it may take anywhere from 8 to 10 weeks to complete. Please keep in mind there could be delays due to the donor or scheduling. Once the eggs are shipped to your doctor, the scheduling of the egg thaw, fertilization and transfer to you is between you and your doctor.
Q: Blood type is important to us; can we get the donor's blood type?A: We ask the donor's to provide their blood type when they apply to become a donor. If we have that information, we would be happy to let you know what it is.
Q: How do I choose my donor?A: The final decision is yours to make. Recipients base their decision on many different personal considerations, but most look for a donor who is generally a good physical match to your overall family profile. We will assist you with narrowing down some options.
Q: Are all the oocytes I get from the same donor?A: The donor you choose will be the only source of oocytes provided to you.
Q: How do you insure there are no mix-ups on the donors?A: There are very strict guidelines and careful oversight for our retrieval center to insure that all the donor eggs are labeled appropriately and the correct donor oocytes go to the correct recipient. We undertake numerous internal audits and meet all criteria outlined by all regulatory agencies.
Q: What is classified as a good quality mature egg for vitrification?A: TWEB only freezes mature oocytes that display a first polar body, which is an indication that they are mature, and look normal under the microscope. We do not freeze any oocytes with visible cytoplasm defects or that do not have a first polar body.
Q: Is the quality of frozen oocytes as good as the fresh eggs?A: Egg quality is generally measured by the quality of the embryo after fertilization. It is common to see a variation in embryo quality even with fresh donor eggs. We can only determine egg maturity as there is no mechanism available to determine which eggs will make the highest quality embryos.
Q: At what day are the eggs frozen (i.e. day 3 or 5)?A: When we are freezing oocytes, not embryos, they are frozen (vitrified) soon after egg retrieval has been completed and the eggs examined under the microscope for maturity.
Q: Why haven't all the available donors shown already been fully screened?A: We have over 450 active donors at any given time and it would be financially impossible to fully screen every donor (each would cost upwards of $3,000). Additionally, some donors are never chosen or decide not to remain on the active roster if they are not quickly selected. We poll our donors regularly to ensure they wish to remain on the roster, and remove those who do not wish to wait to be selected.
Q: What are my overall chances of getting pregnant with frozen oocytes?A: The results using our eggs are not only dependent upon individuals working for TWEB. End users (laboratory staff at clinics utilizing eggs from TWEB) play a significant part in successful outcomes. As a result, our outcome measures reflect the variation that is present across all IVF centers.. We have developed a training program where our Scientific Director travels to individually assist embryologists in clinics who use eggs for their patients for the first time. As a result, clinic outcomes are steadily improving. Survival and fertilization rates average about 90%, which is similar to statistics in many published scientific papers. The ongoing pregnancy rate on a per-cycle basis with eggs from The World Egg Bank is approximately 55%. Considering all of the factors that go into a cycle, and the variables beyond the control of TWEB, we feel this is a good outcome, and reflects a true probability of success.
Q: How do I interpret variations in pregnancy rates provided by other egg banks?A: The World Egg Bank reports pregnancy rates based upon each time an egg warming cycle occurs. For example, if Patient 1 has one warming cycle and becomes pregnant, and Patient 2 has one warming cycle and fails to become pregnant, The World Egg Bank would report the results of these 2 cycles as a 50 % pregnancy rate. If Patient 2 purchased a second set of eggs from TWEB and became pregnant with that set of eggs, TWEB would report the results of these 3 egg warming cycles as a 67 % pregnancy rate (2 of 3). However, others often report the pregnancy rates on a per-patient basis (and not a per-cycle basis). Under such a calculation using the example above, the other egg banks may report a 100 % pregnancy rate (2 of 2 patients became pregnant when 3 cycles took place). This type of calculation is often categorized as a cumulative pregnancy rate. When comparing statistics from different egg banks, one should be sure that the calculations are performed in the same manner. This way, the actual comparisons are fair and one is not comparing apples to oranges.
Another important difference among pregnancy rate reporting is whether the criteria for cycle cancellation are the same. If one egg bank is more likely to cancel a cycle than another, then that bank might have better statistics overall, because fewer "at risk" cycles were allowed to proceed. If a cycle is cancelled before an embryo transfer occurs, then that cycle is not included in the calculation of pregnancy rates based upon a per cycle basis. For example, if a clinic cancels a cycle because they did not obtain good quality Day-5 embryos for transfer versus Day-3 embryos, the pregnancy results are likely to be higher. Under this scenario, one egg bank might have better success than another as measured on a per-transfer basis, but when measured on a per-cycle-started basis, they might not. This is another important area where the comparative statistics between programs can be misleading. The World Egg Bank calculates pregnancy rates according to every cycle where its eggs are used.
Since the statistic of pregnancy rate becomes a very competitive factor when a recipient chooses a doctor or source of donor eggs, there also are other means by which commercial egg banks might operate to make their pregnancy rates higher than they otherwise would be. For example, one commercial egg bank will not allow couples to utilize eggs from their bank if the couple has indications of male factor infertility or if the couple wishes to perform pre-implantation genetic screening on the embryos. Excluding such patients from the pool of patients utilizing cryopreserved eggs is likely to increase the overall pregnancy rate, because the patients with a lower chance of success are excluded from the population of patients using cryopreserved eggs. The World Egg Bank does not discriminate against such patients; we understand that they may have various factors that will influence their own individual chances to become pregnant. We do recommend consultation with your physician when making this important decision.