Embryo Banking in IVF: An Approach That Arrests the Adverse Effects of the Biological Clock
An ever increasing number of American women first seek IVF treatment in their late 30’s or early 40’s.This trend is in large part due to the fact that more and more women are choosing to defer childbearing until they have fulfilled their career aspirations. While such deliberate deferment is understandable, it nevertheless poses significant problems, because women in their late 30’s and early 40’s have about one half the chance of having a baby following IVF than do women in their early to mid 30’s. There are two primary reasons for this:
First is the fact that advancing age beyond 35 years is accompanied by an inevitable and progressive increase in chromosomal egg abnormalities (aneuploidy) which lead to “incompetent” embryos that cannot propagate viable pregnancies. That is why we see a profound and steady decline in IVF success rates as well as an increase in chromosomal miscarriages and birth defects such as Down’s syndrome with advancing maternal age.
Second, as women get older, there occurs a progressive decline in their ovarian egg supply. This so-called “diminished ovarian reserve” (DOR) results in less eggs being accessible via egg retrieval and consequentially, fewer “competent” embryos available for transfer to the uterus.
Most women/couples would like to have more than one child. This desire is no less prevalent in older women. However, by the time the older woman decides to do IVF, goes through the process successfully, has a baby, completes breastfeeding, and thereupon re-establishes regular menstruation in order to try for another IVF baby, a period of 2-3 years will have elapsed. While such a hiatus would usually be of little consequence to a young woman, for an older woman such a delay could seriously impact her “biological clock” so as to drastically reduce her chance of having another baby with her own eggs.
Egg/embryo banking offers a potential solution for older women and those with DOR who wish to minimize the relentless effect of the biological clock. The process involves undergoing several IVF stimulation egg retrieval procedures in relatively quick succession, and then freezing/banking all viable embryos for future dispensation, rather than having them transferred to the uterus immediately. Such embryo “stockpiling” would literally stop the biological clock in its tracks, allowing for the subsequent elective thawing of one or two frozen embryos at a time in future frozen embryo transfer (FET) cycles. This process would avert the risk of progressive declining egg/embryo “competency” over time.
The concept of embryo banking/stockpiling would not have been feasible even 5 years ago, since it was not until quite recently that we became able to reliably identify chromosomally normal (“competent”) embryos for selective banking. Embryo freezing technology has also evolved dramatically over that time. Just a few years ago, the freezing process took a serious toll on embryos, severely damaging up to 50% of them in the freeze/thaw process. But that was then…Today, through the adaptation of comparative genomic hybridization (CGH) technology to egg and/or embryo selection we are able to much better identify “competent” embryos for banking and stockpiling. In addition, the recent introduction of much improved egg/embryo freezing through ultra-rapid cryopreservation (i.e. vitrification) eliminates most of the potential damage incurred to “competent” embryos during the freezing and thawing process. In fact, in IVF centers of excellence, the frozen embryo transfer (FET) process using vitrified/thawed embryos now yields the same IVF success rate as when fresh embryos are transferred!
These innovations (CGH and Vitrification) have not only made embryo banking/stockpiling feasible, but have rendered the approach a most appealing option for older women and women with DOR who seek to undergo IVF using their own eggs.
This having been said, CGH is not an indispensable part of embryo banking. The process can be done without it. But, given the inevitability of an age-related increase in the incidence of chromosomal abnormalities in the egg/embryo, it would be impossible for patients to know whether they have stored “competent” embryos and which ones to transfer to the uterus for the best chance of success when the time comes.
I want to emphasize that CGH does not improve embryo quality. It is an efficiency tool that allows us to select “competent” embryos for transfer and thereby dramatically improve the baby rate per embryo transferred. It is also well to bear in mind that aneuploidy not only reduces the chance of a successful pregnancy but it is also the cause of miscarriages and many birth defects (e.g. Down’s syndrome). Thus CGH embryo selection not only improves IVF success (per embryo transferred), but it also reduces the incentive to transfer multiple embryos at a time, thereby virtually eliminating the occurrence of high-order multiple pregnancies (triplets or greater).
Proudly, we at SIRM were the first to introduce CGH embryo selection into the clinical IVF arena. Since then, we have reported hundreds of successes using this approach, which is finally starting to gain wide acceptance in the IVF field. We were also among the first in the United States to supplant conventional egg/embryo freezing with “vitrification.” It is against this background that we now provide selective embryo banking/stockpiling to an ever increasing number of older women and women with DOR. We have already witnessed the profound benefits of such an approach.
Finally, embryo banking/stockpiling would also have appeal to younger women who plan on deferring having children until later in life – or who want to at least have the option available, should their life/career path so dictate. Even some fertile women for whom IVF would otherwise not be necessary could fall into this category.
Through our technology and package pricing, we at SIRM have attempted to make this approach relatively accessible to those that need or desire access to this advantage.