The freezing of human eggs for childbearing purposes is a technology used by in vitro fertilization, or IVF, clinics to help provide more options for women who want to eventually have children but who may be facing circumstances that make future conception unlikely. Like previous advances in fertility treatments, egg freezing is not without controversy, but as more and more women opt for this technology, it will likely become part of the standard offerings at fertility clinics nationwide, says Dr. Michael Tucker of Georgia Reproductive Specialists.
Reasons
Some women freeze their eggs in preparation for cancer treatment which may destroy egg cells and ovarian tissue. Other women may freeze their eggs during their 30s to ensure reproductive ability later in life, perhaps after establishing a career or finding a mate with whom they would like to have children. In some cases, women undergoing IVF may choose to freeze eggs for later IVF attempts instead of producing multiple embryos. Another use of freezing oocytes is in the case of donor eggs, which allows them to be stored for a period of time before use instead of needing to be fertilized and implanted immediately.
Biology
A woman is born with all of the eggs she will ever have in her life. Because the quality of these eggs declines over time, as women age, it becomes more difficult to conceive and more likely that the egg will produce a child with a birth defect. As the article "Why Women are Freezing Their Eggs" at ForbesWoman by Camilla Webster explains, while a healthy 20 year old has an 82 percent chance of getting pregnant in a given year, a 35 year old has only a 52 percent chance.
Technology
The freezing of eggs can be done in two ways. Individual eggs can be frozen after being removed from the ovaries and frozen in a protective solution. Alternately, ovarian tissue cryopreservation is the freezing of a sample of ovarian tissue containing multiple eggs. According to ForbesWoman, over 1,000 babies have been produced using frozen and thawed eggs as of April 2010. Both human sperm and complete embryos have been frozen successfully for decades using similar technology.
Process
To get eggs for freezing, a woman must first have injections of a drug to cause her to develop several eggs. She is then monitored the eggs are retrieved when they are mature but before they are released from the ovary. The doctor uses a transvaginal ultrasound, a device inserted into the vagina that uses ultrasound waves to produce an image of the reproductive system on a computer, to locate the position of the eggs for retrieval. The eggs are removed via a long needle and then frozen and stored.
Considerations
In general, egg freezing should be done before age 35 to be effective, since women older than this are more likely to have problems with egg quality. However, some clinics allow egg freezing up to age 40. The procedure is not typically covered by health insurance since it is considered experimental, despite being offered by IVF clinics nationwide.
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