"Even having the option to store their eggs can give them a psychological boost. They might have more faith in their recovery and that there is something to live for."
Young, fertile women
Should egg-freezing success rates improve substantially, many experts see great potential in egg banking for women in their 20s who want to delay childbearing to later in life. Beginning in her 30s, a woman's chances of becoming pregnant decline.
"Putting your eggs on hold is very appealing," says Gordon. "I'm hearing this from younger women who are looking at this as giving them some control over their lives. It's the long-term planning that is appealing. I think people fear they may be infertile down the line."
Egg cryopreservation may also become a routine back-up plan for women in their 20s who undergo sterilization.
"If you want to have tubal ligation at a young age, go ahead and freeze some eggs first," says Sher. "These kinds of opportunities have immediate application."
Women Nearing Menopause
Egg cryopreservation, at present, has the least to offer women who are approaching 40 or are in their 40s and who see their chances of becoming pregnant declining with age. Banking eggs in the "eleventh hour" of one's fertility is an attractive idea for women who aren't married or aren't ready to become pregnant just yet. But these women shouldn't get their hopes up, several experts caution.
"As we sit here today, this technology is not applicable to that type of patient," Davidson says. "When you are 39 or 40 those eggs are already past their prime."
Sher agrees that egg freezing is most likely to be successful with younger eggs. Older women may be better off trying in vitro fertilization with donor sperm and freezing the resulting embryos. Older women could also wait until they want to become pregnant and use donor eggs if their own eggs fail.
However, there is another advance on the horizon for older women who wish to become pregnant using their own eggs. Researchers from New York University Medical Center announced last month that they have succeeded in removing the cell nucleus--containing the genetic material--from the egg of an older woman and inserting it into the "denucleated" egg of a younger woman. A denucleated egg contains the cytoplasm, or outer part of the cell, but the genetic material has been removed. Four of seven "reconstructed" eggs in this study matured and displayed the normal number of chromosomes, the researchers reported.
Researchers propose that it may not be the genetic material of an older woman that causes fertility problems but other elements of the egg--elements that could be replaced with the use of younger donor eggs, adds Sher, who says Pacific Fertility Centers will soon begin a small pilot study of this technology.
Scores of other questions and controversies loom as egg cryopreservation becomes a part of the medical landscape.
For example, do frozen-thawed eggs produce a higher risk of genetic abnormality? According to researchers from South Korea writing in this month's issue of the journal Fertility and Sterility, eggs that were frozen at an early stage of development and then thawed showed an increased incidence of chromosomal abnormalities compared to eggs that were not frozen.
And there are many economic and ethical questions, as well, says Cullen. Such as: Who will make decisions regarding the fate of frozen eggs? Earlier this month, New York state authorities held hearings to debate the fate of thousands of frozen embryos that are unclaimed. Egg freezing could add to this significant issue.
"There are many, many moral and ethical dilemmas around all this. Who owns the tissue if something happens to the patient?" Cullen says.
It also remains unclear who will take the lead in establishing the first commercial egg banks: infertility clinics, sperm banks or another industry?
And who will set the rules? In general, the infertility field is self-monitored, with clinics abiding by voluntary guidelines, Reame notes. Egg banking may prove reason enough for limited government oversight, she adds.
"I think the banking of reproductive tissue is going to haunt us more than any other issue," Reame says. "One of the things we'll have to grapple with soon is the issue of licensing and developing adequate, minimum standards for oocyte banking. We are just now figuring out what the practice guidelines should be for semen banking: how to store semen, record-keeping, handling, processing and documentation."
The lack of regulations in semen banking, she notes, has resulted in 12 documented cases of HIV transmission as well as concern that too many children are being born from the same donors.
"We know that mistakes, errors, negligence and misconduct can happen with semen banking. And we know from [the alleged misappropriation of eggs and embryos at] the University of California, Irvine, that embryo preservation has had problems, too. Oocyte banking could produce the biggest issues yet," she says.