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Published online 24 October 2007 | Nature 449, 958 (2007) | doi:10.1038/449958a
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Little consensus on egg freezing
Latest data fail to resolve debate over safety and efficacy.
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I am a big advocate of women being correctly informed on issues concerning their reproductive health. Egg-freezing has been the standard of care in Italy since 2004! After doing extensive research about egg freezing, I have found that there have been over 500 babies born worldwide and of the ones that were followed-up, no increase in birth defects were seen. As a culture I think that we should look at egg freezing as a great advance in reproductive choice. I have found a company called Extend Fertility, who offer elective egg freezing and their website (www.extendfertility.com) is really full of information!
I think it's all right for women to preserve their eggs for "social or career reasons." Years ago, a woman having a child at forty risked dying before that child was grown, but people are living longer, healthier and more active lives. Still, the community is right to explore all possible downsides of social egg preservation, including the reasons why it makes people uncomfortable.
If IVF laboratories froze eggs instead of embryos it would be a tremendous boon for stem cell science as hundreds of thousands of eggs would become leftover and available for nuclear transfer. Proving the safety and efficacy of these techniques is of paramount importance.
If IVF laboratories froze eggs instead of embryos it would be a tremendous boon for stem cell science as hundreds of thousands of eggs would become leftover and available for nuclear transfer. Proving the safety and efficacy of these techniques is of paramount importance.
The slow freeze method of egg freezing originated more than 20 years ago. Initially, success rates were very low (as with any new technology like IVF and ICSI). Unfortunately, embryo freezing overshadowed egg freezing for many years and became accepted in most IVF centers. More recently, slow freeze protocols that were successful for embryo freezing were tried for egg freezing, with disappointing results. However, by modifying the slow freeze method to adjust for egg physiology, the success rates of egg freezing (live birth rates) are not significantly different compared to the standard embryo freezing success rates. It is not just the freezing chemical solutions, but the experience of the lab and the embryologist who understands the prinicples of cryobiology that makes a difference. Also, patient selection is critical. Our data, presented at ASRM showed no difference in success using frozen eggs as long as the woman was under age 35 years. We compared the success of egg thawing from healthy donors and actual patients <35 years who froze and thawed their own eggs and found no difference in success rates. 14 babies have been born and 10 more are on the way with no increase in birth defects. Women requesting to thaw (not just freeze) their eggs should be given accurate data abou their clinic's personal experience with oocyte thaw and pregnancy rates. Anyone can freeze any type of tissue, what really matters is the thaw procedure and a successful outcome. Thanks. David Diaz West Coast Fertility Centers
Egg freezing is an experimental procedure, a position I share with the ASRM. However no one should deny women the choice to make an informed decision about their genetic legacy. There is recent data showing egg freezing success rates have significantly increased in the past 3 years. Thus, to recommend delaying pregnancy to a point later in life will only mean increased risk of birth defects and loss of fertility potential. As with any medical breakthrough, there must be an experimental phase leading to successful implementation. During this phase it is paramount that patients be properly informed about the risks, benefits and alternatives of the technology. It is estimated that 100,000 births are needed to determine true safety. But the reality is, as many women are preserving their eggs for future use, we may not reach this number for more than a decade--- too late for any woman currently over 30. - Dr. John Jain, Santa Monica Fertility Specialists