Babies on Ice
Babies on Ice
Newspaper Article
By: Viv Groskop
Date: March 4, 2006
Source: Groskop, Vic. Guardian Newspapers Limited. "Babies on Ice." (March 4, 2006).
About the Author: Viv Groskop is a journalist who writes for the Guardian newspapers in the United Kingdom. She contributes regularly to the New Statesman, a British publication that was started in 1913. She has also written for the (London) Independent and Times, among others.
INTRODUCTION
As women have become progressively more involved in the workforce, the age at which they begin to have children has risen steadily. Often they choose to put off childbearing until well into their thirties, and sometimes beyond. In addition to career aspirations, women often cite the lack of a stable relationship and/or second income among the reasons for not having babies when they're at their most fertile.
Females are born with a finite supply of eggs that begin to "age out" of fertility as they pass their middle and late twenties. Fertility decreases annually after thirty, the number of viable eggs diminishes, and the odds of miscarriage or pregnancy complications increase, although it's important to remember that the relative fertility of each individual is determined by a complex amalgam of genetics, personal history, and other health factors. Complications such as kidney disease, high blood pressure, and diabetes all affect an individual's chances of successful pregnancy and uncomplicated delivery, as do lifestyle factors such as diet, drug or alcohol use, exercise, and the like. While the viability of individual eggs inevitably erodes over time, the ability of a woman's uterus to sustain a pregnancy is far less age limited: it is physically possible to carry a pregnancy to term even when well beyond menopause.
It has been possible to harvest and preserve human sperm for decades, and cryopreservation (freezing) techniques have improved to the point where it is possible to maintain its viability for ten or more years. The same technology has evolved over the past two to three decades to allow human embryos and eggs to be frozen for later use by either the original donor or for another, infertile woman. Embryos (at the stage of several cell divisions after fertilization) have been successfully frozen and thawed more often than have unfertilized eggs.
PRIMARY SOURCE
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SIGNIFICANCE
Cryopreservation for unfertilized eggs was originally intended for women who were either about to undergo medical procedures that could interfere with fertility or that had potential implications for DNA alteration in unfertilized eggs. The use of egg freezing to delay healthy or lower-risk childbearing, or to donate eggs—analogous to the way in which men donate sperm to banks—evolved only within the past several years, because it is far more difficult to freeze a human egg than it is human sperm. This is mainly because the oocyte (egg) is the largest cell in the human body, and it contains a significant amount of water. When frozen, the water turns to ice, which can damage the cell's membranes. Freezing technology had to be developed that could eliminate the water and freeze the egg and its cellular contents without damaging either the cell structure or its genetic contents.
Unlike thawed sperm, which is often simply placed inside the uterus or at the cervix of the woman seeking insemination, thawed eggs cannot simply be put back into a woman's body to be fertilized—They must be fertilized by means of assisted reproductive technology (ART), outside the body. As technology advances, however, it will become progressively easier and less costly to harvest, thaw, and fertilize human eggs, whether for the woman from whom they were harvested or for donation to another.
Because egg production is fixed, meaning that a female is born with all of the egg follicles she will ever have, eggs age over time and become less viable—less easily fertilized and carried through a successful full-term pregnancy. With each month after the onset of menses, the quality of the eggs released can vary, with significantly reduced potential fertility after the age of 35. By harvesting eggs and freezing them in her 20s or early 30s, a woman may be able to postpone a healthy and viable pregnancy for a decade or more.
Scientists hope to develop a freezing technology that will give unfertilized eggs the same potential viability as frozen embryos. During the first decade of the twenty-first century, Japanese scientists developed an effective method that eliminated the formation of cell-wall damaging ice crystals. This advance may boost the potential fertility rates of thawed eggs from 1:100 to 10:100, making it far more cost-effective. This may make it progressively more possible for women to use egg freezing to postpone child-bearing until they are ready to do so, rather than feeling that their "biological clock" is running down.
Several fertility clinics specializing in the harvesting and freezing of human eggs have been opened, primarily in larger cities in the United States. For varying fees, unfertilized eggs are harvested, frozen, and banked for later use. At present, fertility and viability rates for the thawed eggs remain considerably lower than thawed sperm—in part because eggs are generally fertilized singly, with the addition of several million sperm. As technology improves and fertilization rates for thawed eggs increase, it will become more and more affordable for women who wish to delay child-bearing to avail themselves of this possibility.
FURTHER RESOURCES
Books
Bauer, M.W., and G. Gaskell, eds. Biotechnology: The Making of a Global Controversy. Cambridge, UK: Cambridge University Press, 2002.
Blank, R.H., and J. Merrick. Human Reproduction, Emerging Technologies, and Conflicting Rights. Washington, DC: CQ Press, 1995.
Gaskell, G., and M. W. Bauer, eds. Biotechnology 1996–2000: The Years of Controversy. London, UK: Science Museum, 2001.
Harris. J., and Søren Holm, eds. The Future of Reproduction: Ethics, Choice, and Regulation. Oxford, UK: Oxford University Press, 1998.
Saetnam, A.R., N. Oudshoorn, and M. Kirejczyk, eds. Bodies of Technology: Women's Involvement with Reproductive Medicine. Columbus, OH: Ohio State University Press, 2000.
United States Department of Health and Human Services. 2003 Assisted Reproductive Technology Success Rates: National Summary and Fertility Clinic Reports. Atlanta, GA: Centers for Disease Control and Prevention, December 2005.
Periodicals
Abdalla, H. I. "A National Oocyte Donation Society Is Needed." Human Reproduction. 11, no. 11 (November 1996): 1255-1356.
Abdalla, H., and J. W. Studd. "Egg Donation and Medical Ethics." British Medical Journal. 299 (1989): 120.
Gosden, R.C. "Maternal Age: A Major Factor Affecting the Prospects and Outcome of Pregnancy." Annals of the New York Academy of Science. 442 (1985): 45-57.
Hansen, J. "Older Maternal Age and Pregnancy Outcome: A Review of the Literature." Obstetrics and Gynaecology Survey. 41 (1986): 726-734.
Salter, B. "Medicine, Civil Society and the State: Continuities in Biopolitics?" Swiss Political Science Review. 9, no. 2 (2003): 135-142.
Salter, B. "Who Rules? The New Politics of Medical Regulation." Social Science and Medicine. 52, no. 6 (March 2001): 871-873.
Web sites
International Assisted Reproduction Center. "Fertility Options." 2006 〈http://www.fertilityhelp.com/CM/AboutAssistedReproduction/Fertility_Options.asp〉 (accessed June 21, 2006).
Reuters. "Japan Experts Devise New Human Egg Freezing Method." June 19, 2006 〈http://www.alertnet.org/thenews/newsdesk/l1994843.htm〉 (accessed June 22, 2006).
American Surrogacy Center (TASC). "TASC Articles: Medical." 〈http://www.surrogacy.com/Articles/〉 (accessed June 21, 2006).
San Diego Union-Tribune. "Commercial Freezing of Human Eggs Has Backers, Opponents." September 29, 2004 〈http://www.signonsandiego.com/uniontrib/20040929/news_1c29eggs.html〉 (accessed June 22, 2006).