CGH Embryo Selection Could Open the Door to IVF Insurance Coverage

26 May
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Most couples experiencing infertility are willing to make enormous sacrifices to have a baby. Why then, with IVF being at least 3 times more likely to succeed than any other infertility treatment, do less 10% of couples in the U.S for whom IVF is needed currently receive such treatment annually? I believe that there are two main reasons for this:

1. Most infertile patients who need IVF are under-informed regarding the relative advantages that IVF has over other infertility treatments.

2. The lack of access by most U.S citizens to IVF insurance coverage makes the $13,000 to $15,000 price tag per treatment cost-prohibitive for most. The question arises as to why most insurance providers are reluctant to cover infertility treatment in general and IVF in specific. Here are a few reasons why:
a. Lack of accountability in reporting IVF success rates. There is no National body that provides independent verification of the accuracy of the statistics reported by individual clinics.
b. Lack of uniformity in the standard IVF care delivered at different centers. Success rates can vary from single digits to over 50% per treatment, depending on the center.
c. The tendency of IVF practitioners to transfer multiple embryos at a time in order to increase the chances of success. This has led to a virtual explosion in the rate of high-order multiple births (triplets or greater) and the associated medical costs due to prematurity-related complications. These can lead to lifelong, costly medical care – a losing proposition for insurance companies.

In this first post, I’d like to discuss the last point (c) above:

Because the ability to reliably identify the embryo(s) most likely to make a baby has been more of an educated guess than a science up to this point, one woman may fail to achieve a pregnancy after having 3 embryos transferred, while another may conceive triplets from the same number of embryos.

The recent introduction of Comparative Genomic Hybridization (CGH) as a tool to identify those embryos that in the vast majority of cases will produce babies (i.e are “competent”) has changed this dynamic. Since the “competency” of an embryo is by and large linked to its chromosomal integrity and CGH analyzes all of the chromosomes in the egg/embryo, performing such testing eliminates much of the guesswork. Also, as the majority of miscarriages are caused by chromosomal abnormalities, pregnancies arising from CGH-normal embryos are much less likely to be lost in early pregnancy.

The fact is that despite their microscopic appearance, most embryos (>60% even in young women) are chromosomally abnormal (aneuploid). Such embryos are invariably “incompetent” and will either fail to implant at all, be lost early in the pregnancy (1st trimester miscarriages) or should they survive, result in a chromosomal birth defect such as Down’s Syndrome.

Embryo aneuploidy is primarily (but not exclusively) due to chromosomal irregularities that arise in the egg rather than the sperm. The fact that the percentage of aneuploid eggs increases with the age of the egg provider serves to explain why the incidence of infertility, miscarriages and chromosomal birth defects all increase as women age beyond their mid-thirties. Thus, the birth rate per transferred embryo is about 20% in women under 35 years of age , 10-15% by age 40 and well under 10% by the time the woman reaches her mid forties.

By being able to identify competent embryos prior to transfer, birth rates per embryo transferred could be greatly improved and accordingly allow for the transfer of no more than two (2) “competent”, CGH-normal embryos at a time. This would virtually eliminate high-order multiples and establish a “win-win” situation for all involved.

In 2007 we reported in the journal, “Fertility and Sterility” on a study where we used CGH to identify “competent” eggs. Knowing that it is the chromosomal integrity of the egg that (with the exception of male infertility cases) determines embryo “competency” we then selectively transferred up to 2 advanced embryos (blastocysts) that were derived from CGH-normal eggs. The result was about a 70% birth rate per blastocyst transferred. This is at least 2- 3 times higher than has been possible in the past. In this study, the multiple pregnancy rate was also several times lower and the rate of miscarriages, much reduced.

We have todate transferred embryos derived from CGH-tested eggs and embryos, to more than 300 women. This has thus far resulted in >100 births and at least an equal number of pregnancies, still ongoing. We are convinced that use of this CGH technology will progressively grow over the next 5-10 years an in the process will set a new “efficiency standard” in the ART arena.

4 Comments

  • The biopsy of a blastomere (embryo cell) for CGH is much easier and more rapidly performed than that which is required for PGD/FISH. Staining requirements necessitate that with PGD/FISH requires the blastomere removed is completely intact so as to insure maintenance of the structural integrity of each chromosome. On the other hand, CGH, since it is a DNA-based test, does not require such a meticulous result. Thus when it comes to PGD/FISH it is not uncommon for the embryologist to have to repeat the biopsy for second blastomere. With CGH this is hardly ever needed.

    For these and other reasons, blastomere biopsy for CGH is much less traumatic to the embryo than is PGD/FISH.

    While nothing is ever absolute, false positives and false negatives are rare with CGH but in about 10-15% of cases we do encounter inconclusive results where one cannot make a definitive diagnosis.

    Geoff Sher

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