The ability to preserve human eggs has been a “home run” in reproductive medicine. Previously hindered by technical difficulties, in experienced hands currently, eggs which have previously been cryopreserved with the vitrification method now approach the performance of freshly retrieved eggs. This is a great development that has several important applications – couples may wish not to have all their eggs inseminated in order to reduce the number of “excess” embryos produced in their IVF cycle. Women may wish to freeze their eggs in order to preserve their reproductive potential as they age.
Egg donation – Fresh vs. Frozen
The area of egg banking which has seen the most rapid acceptance is for oocyte/egg donation. Fresh egg donation is a highly successful approach to infertility that makes up about 10% of all IVF cycles in the US. It has many advantages:
• High success rates with existing technology in experienced ART programs;
• Well-established agencies with availability of most desired donors.
However, there are also many disadvantages, which include:
• Cost; difficulty of obtaining certain racial/ethnic oocyte donors;
• Need to coordinate timing of donor and recipient;
• Inability to predict/guarantee response pattern of donor; recipient pays for cycle regardless;
• Having too many “leftover” embryos in some instances.
Egg Bank Models
In the most recent US data from the Society for Assisted Reproductive Technology (SART), the real impact of banked egg donation has become apparent. Currently, a quarter of all egg donation cycles in the US use banked eggs. The report does not specify the source of the eggs and we know there are various approaches to egg banking. On a small scale, a doctor’s office or fertility practice can recruit donors for egg banking, or offers reduced fees for fresh “egg sharing” cycles, with the excess eggs being frozen. Typically this would not result in much donor choice for the recipients.
It seems that most of the banked egg cycles in the US are the result of a different model, that of a large egg bank. There are several large egg banks currently, with similar basic approaches, but some important differences. Some banks work exclusively with a few of fertility practices; a recipient must have her care in these locations. This may improve quality assurance but also poses a barrier to those not living in the region. Travelling to the primary program center reporting the high success rates may be okay for some, but certainly adds additional costs and stresses.
Another approach is that which has been used for sperm donation for decades – the recipient chooses the eggs herself on-line and the eggs are shipped to her fertility practice. This is the method used by The World Egg Bank for many years, believing that the recipient and her partner prefer to seek care in their own community with doctors and staff they know and trust.
Donor Screening and Choice
The World Egg Bank is the oldest, most experienced and successful egg bank in the US. We perform rigorous screening and testing of donors, undertake a stimulation and retrieval in our own center, and ship 6 or 7 oocytes typically to the recipient’s own ART program where they are thawed and inseminated. One or two embryos can then be transferred, and possibly a few embryos frozen, although this is often not the case.
The most obvious difference in egg banks is donor availability. Usually one can register on line and get a clear picture of your options that way. It helps if there is a live person on the phone, also. More experienced banks tend to have more donors and greater variety. Whether there are pictures (child or adult) of the donor and how much donor information is given to the recipients varies among banks. Whether the donor agrees to become known to her genetic offspring at some point in the future is another variable that is important to many; this varies among banks.
Screening and testing of egg donors is for the most part mandated by the FDA, although there are some additional tests which are desirable but not mandated or used in all banks. Aside from medical, hormonal and genetic testing, most banks do psychological screening via an interview and a standardized test like the MMPII; the American Society recommends this for Reproductive Medicine.
Costs and Financial Packages
It’s important to understand the various financial packages that may not be straightforward. Guarantees regarding the condition of the warmed oocytes are usual, but not all the same. The World Egg Bank guarantees that at least four eggs will survive the thaw process if 7 are shipped. It is expected that not all eggs will fertilize or develop into good embryos, just as with fresh donor egg cycles. If you are guaranteed “a baby or a refund” be careful to lay out the full costs if you have to go through 6 cycles to qualify for the refund (some which are frozen embryos), switch donors mid-stream, pay additional donor or agency fees, re-test the patient between cycles and the cost of medicine per cycle. You will find the refund, if you do not become pregnant, falls far short of your actual costs.
Like with fresh IVF cycles, it can be hard to decipher pregnancy rates among egg banks. It is important to compare apples to apples. The most recent report from SART (Society for Reproductive Technologies) showed that overall live birth rates per attempted cycle between fresh and frozen banked egg cycles are similar – 50% pregnancies for fresh cycles vs. 43% for frozen egg donation cycles, with transfer of an average of 1.7 and 1.6 embryos respectively.
It is more tricky to figure out the pregnancy rates per bank, since the source of eggs is not disclosed in the SART report. So we are left with a hodge podge of reporting techniques on the banks’ websites. Some banks report very high pregnancy rates, but these cycles may have all been conducted in one program. In some cases, extra eggs have been warmed (at extra cost), if some of the eggs did not survive well initially. Other banks will lump several cycles together in reporting their pregnancy rates. You must compare ‘per single embryo transfer’ rates. Keep in mind, though, that the possibility of having one or two frozen embryos result from the purchase of one set of eggs is important in the overall decision making, since the pregnancy rates with frozen embryo transfer from donor eggs is high (37% live birth rate per warming per SART data). Currently, there are no standardized reporting requirements for the egg banks, unlike the requirements of the fertility practices.
How does one choose an egg bank? There is no single variable that works for all recipients. Knowing that there is a staff of people available to you by phone, all working for your best outcomes, is very important. Receiving simple, straightforward information about the donor, the finances and likely outcomes is important. Knowing that the bank is highly experienced and can help recipients all over the world, with a variety of different needs and goals, is important too.
Dr. Patricia McShane has been involved in reproductive medicine since the early days of IVF in the US. She has been the medical director for a large private fertility center as well as taught and practiced in academic medicine. She was very gratified when egg freezing became a practical clinical reality. Dr. McShane is the medical director of The World Egg Bank.