Infertility Insights
Gonadotropins and Abnormal Embryos
One of the greatest fears among patients undergoing in vitro fertilization or other Assisted Reproductive Technologies (ART) is that the steps necessary to achieve this much wanted pregnancy may put the embryos that are created at risk for genetic abnormalities.
We have known for many years that nearly half of embryos created using IVF are genetically abnormal on day 3 after retrieval. We can measure this directly since embryonic cell testing such as pre-implantation genetic diagnosis (PGD) of comparative genomic hybridization (CGH) can tell us the genetic makeup of these embryos.
Many of my patients have voiced their concerns that the use of the IVF medications, especially the stimulatory gonadotropins (such as Follistim®, Gonal-F®, Bravelle®, Menopur®) is such an un-natural situation that it causes genetic abnormalities in the eggs, and hence the embryos created from them. These abnormalities could then lead to the failure of the cycle to create normal embryos and hence the failure of the cycle. Although the overwhelming majority of Reproductive Endocrinologists vehemently disagree with this assertion, someone has now given us the data to show directly that it is not.
Researchers in Spain, led by Elena Labarta, MD, devised a study in which they used egg donors to answer this question. They used donors, for these patients are all young and of proven fertility, therefore making the chance of genetically abnormal eggs far less common than infertile females. In half of them they used no gonadotropin stimulation, and in the other half they used standard IVF stimulation protocols. In the un-stimulated group, testing showed that 35.3% of the embryos were genetically abnormal, while in the stimulated group 34.8% were abnormal. There is statistically absolutely no difference between these groups, therefore no increased risk from the use of gonadotropins.
This proves what I have believed for a very long time – that although the manner we stimulate the ovary to allow for the retrieval of a larger number of eggs is outside what the body would generally do on its own, it is not harmful to the egg or the embryo. Natural cycle IVF (a cycle with no stimulation at all) should therefore fade into the background of reasonable ideas that serve no great clinical benefit.
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