The child could have been born in 1993 but its first experience of the world came 13 years later, or nine months after an embryo was pulled out of the freezer at a Spanish fertility clinic.
The clinic in Barcelona is claiming the world record for having brought about the birth of what could be termed the world's oldest baby. Conceived in a laboratory dish, but not used at the time, the embryo sat at minus 196C in a freezer cabinet awaiting its adoptive parents.
The original parents had donated the fertilised egg to the Instituto Marqués clinic after a sibling was born from a separate embryo successfully implanted in the mother's womb.
The ability to freeze embryos is useful for couples who have had to go the route of in vitro fertilization (IVF, a.k.a. test tube babies). They can store some embryos while trying to start a pregnancy with other embryos. If the pregnancy doesn't suceeed or if they decide they want still more children some embryos can be thawed out to try to start another pregnancy. One result of this practice is the gradual accumulation of thousands or perhaps tens of thousand of embryos in fertility clinics around the world.
Improvements in techniques to freeze embryos combined with the increasing use of IVF will increase the supply of surplus unused frozen embryos. Some Christian groups think those embryos are real human lives with souls and recruit married couples to try to start pregnancies with frozen embryos (a.k.a. embryo adoption) that are sitting in large numbers in freezers in fertility clinics. But advances in freezing technology and the increasing use of IVF both look set to increase the supply of embryos faster than Christians step forward to adopt them.
One trend I expect to emerge at some point: The ability to freeze embryos is going to become an added enticement for couples to start pregnancies with IVF rather than with good old fashioned sex. Why? Left-over embryos, freezable for decades, will serve as a sort of insurance policy should one or more of their kids die from an accident or disease. When the woman is still healthy enough to produce viable eggs couples could decide to do IVF, produce more embryos than they need, start one or more pregnancies, and then store some embryos in case the need arises or in case they just decide to have more kids when the woman reaches her late 30s or 40s.
Embryos are more robust than unfertilized eggs and embryos are easier to freeze and thaw. Alan B Copperman, MD. Director of Reproductive Endocrinology and Vice-Chairman of Obstetrics and Gynecology at the Mount Sinai Medical Center, says recent improvements in freezing and thawing techniques has increased success rates in use of frozen eggs.
In the fall of 2004, The American Society for Reproductive Medicine (ASRM) issued an opinion on oocyte cryopreservation concluding that the science was "promising" due to the fact that recent laboratory modifications have resulted in improved oocyte survival, fertilization, and pregnancy rates from frozen-thawed oocytes in IVF. The ASRM noted that from the limited research performed to date, there does not appear to be an increase in chromosomal abnormalities, birth defects, or developmental deficits in the children born from cryopreserved oocytes. The ASRM recommends that, pending further research, oocyte cryopreservation should be introduced into clinical practice only on an investigational basis and under the guidance of an Institutional Review Board (IRB). As with any new technology, safety and efficacy must be evaluated and demonstrated through future research.
The problems with egg freezing may eventually be solved by freezing earlier stage germinal vesicle eggs which, among other qualities, have membranes that are more permeable to cryopreservation compounds. But methods to extract eggs that are at that earlier stage might need refinement to get eggs that are relatively less developed.
Advances in egg freezing technology strike me as more interesting and with more implications than advances in embryo freezing technology. Egg freezing has two big potential purposes. First off, women who are looking for Mr. Right can freeze some eggs in case Mr. Right doesn't show up before their fertility declines. Second, egg freezing could become a way to increase the size of the market for donor eggs.
The same Alan B Copperman, MD quoted abave has done a recent survey of a small group of single women who had their eggs frozen. 80% said they would consider using donor sperm if they could never find Mr. Right.
Although the study was small — it involved 20 women — it suggests that the first group to take up the option of egg-freezing are doing so chiefly to take their fertility into their own hands.
“A number of women said they were interested in egg-freezing to take the pressure off the search for relationships,” the researchers said. “Cryo-preservation meant the freedom to wait, and to not settle for a mate because they were in a rush to conceive.”
Women with eggs sitting frozen in a freezer might well become more choosy about men as a result. Take away the sense of a biological ticking clock for reproduction and women may become more reluctant to compromise and less willing to lower their standards in order to find a guy to marry and make babies with.
Technological advances change the trade-offs people face. It changes trade-offs in relationships just much as it does in careers. Advances in assisted reproduction technology (ART) could change human relationships even more dramatically than has the birth control pill and other means of contraception.
In theory the ability to freeze eggs opens up the possibility of a much larger market for donor eggs with greater choices. Currently women looking for donor eggs can only choose among women who they can find to supply fresh eggs. But imagine the world 30 years from now. A woman could choose among eggs that come from eggs frozen over a period of decades and from donors who are no longer young and fertile. Egg donors could produce and store a large number of eggs when they are young and then gradually sell them over a period of decades.
But in many legal jurisidictions around the world a substantial legal obstacle exists for the creation of a donor egg market that spans across generations: Restrictions on the ability to pay for female egg donation services. Some jurisdictions ban the practice entirely. Currently the United States does not allow payment for eggs but only allows payment for the service of creating the eggs.
The United States is one of many countries in which legislation and social norms proscribe the selling of body parts. It is also the world capital of the genetic material market: No other nation trades in DNA so widely and freely. Hopeful mothers and cash-strapped college students have been trading cash for eggs for 20 years, calling the ova a “donation” and the money compensation for time and discomfort, thus avoiding the ban on sales.
How can a woman sell her eggs over a period of decades and claim her sales pay for discomfort she experienced 20 or 30 years ago? Would this claim stand up in court? I have no legal expertise. On the answer to that question hinges the future of a potentially much larger market for donor eggs.
When DNA testing becomes cheap and highly informative (on the outside within 10 years) the value of a small portion of all donor eggs will go up dramatically. Women who can show by genetic testing that they have the genetic sequences that are most in demand (high IQ, desired personality characteristics, good looks, desired hair and eye color, resistance to assorted diseases, etc) will find their eggs suddenly fetch even larger premiums than the current high prices for Ivy League egg donors who want to sell their eggs.
Do you want to sell your eggs? Women who think they might have the right genetic stuff could freeze their eggs now and then offer them for sale 10 or 20 years from now when they can prove with genetic tests that they have the genetic variations that the market most demands. Such women could freeze their eggs now and then if they meet Mr. Right when they turn 40 they can use a few of their eggs then to start a family. Whether or not they meet Mr. Right they can use other eggs from their frozen stash to sell once the market places a high value on their genetic inheritance.
|Share |||Randall Parker, 2006 November 05 02:50 PM Biotech Reproduction|