Does in vitro fertilization (IVF ) work better using fresh human eggs as compared to eggs that were frozen and then thawed? Kutluk Oktay MD and colleagues at the Cornell's Center for Reproductive Medicine and Infertility New York City looked at the relative success rates of using freshly donated human eggs versus thawed eggs to start pregnancies that go to term and produce live births. They compared two methods of freezing called slow-freezing (SF) and vitrification (VF) as well as freshly harvested eggs. IVF was done with intracytoplasmic sperm injection (ICSI). Fresh eggs produced almost 3 times the number of live births as eggs using the best freezing method, slow freezing. (ET stands for Embryo Transfer)
Live-birth rates per oocyte thawed were 1.9% and 2.0% for SF and VF, respectively, before June 2005. Live-birth rates per injected oocyte and ET, respectively, were 3.4% and 21.6% for SFM and were 6.6% and 60.4% for IVF with unfrozen oocytes.
Yet the 21.6% success for the better freezing method is high enough to be usable. That's good news because frozen eggs have a few benefits. First, women who are going to undergo medical treatments (e.g. chemotherapy for cancer) might become sterile or suffer sufficient damage to their ovaries that their eggs would be at risk of producing defective babies. Extracting and freezing eggs from a woman before she undergoes a medical treatment opens up the possibility of still being able to have healthy children afterward if the illness can be cured.
Another reason to freeze eggs is to allow a young woman to store some eggs away to use to have children in her late 30s or 40s when fertility declines drastically.
A third possible reason to freeze eggs is that it opens up the possibility of a much larger market of donor eggs. A woman could have eggs harvested and stored for transport to wherever a market demand for her particular eggs exists. Then buyers could have much larger selections to choose from. Egg donation will become more commonplace if women can have eggs harvested while she is young to be sold for decades afterward.
Many countries do not allow the sale of donor eggs. However, in the massive market called the United States of America egg selling is allowed. One center in Texas even will put together donor eggs and sperm and ship already fertilized embryos to IVF clinics for implantation.
The Abraham Center of Life allows people to order custom-made embryos and have them shipped to an IVF clinic for implantation.
The embryos are created with the eggs and sperm of rigorously screened, "qualified" donors who have never met each other. Conception occurs as the embryo bank fills its orders. Customers can even specify the eye and hair colour that they would like their baby to have.
They can't guarantee the hair and eye color just yet. But with advances in genetic testing fertility clinics will eventually be able to offer high probabilities for sex, appearances, intelligence level (high IQ will become very popular), personality type, disease risks, and other characteristics.
Advances in egg freezing and thawing methods combined with advances in DNA testing and IVF will increase the advantages of using donor eggs and therefore increase the demand for egg donors. See my posts High Intelligence Sperm and Egg Donor Prices Rising, The Growing Market For Donor Eggs, and More Single Women Using Sperm Donors. I also predict the development of a larger market for donor eggs and sperm will make humans more genetically determined and less influenced by their environment. See my post Children Of The Future May Be More Genetically Determined.
|Share |||Randall Parker, 2006 August 22 11:01 PM Biotech Reproduction|