New York scientists say they've enabled two infertile women to produce eggs by grafting their ovary tissue under the skin of their forearms. Radiation for cervical cancer had made one woman, aged 35, sterile, and surgery for benign ovarian cysts resulted in sterility for the second woman, 37.
The grafts are intended to restore fertility for women who undergo treatments that destroy their ovaries, as well as those who undergo premature menopause. Grafts also may help delay the onset of menopause or ease its symptoms, allowing older women to get pregnant. A write-up of the technique, which has been reported previously, appears in the Sept. 26 issue of The Journal of the American Medical Association.Dr. William Keye, director of reproductive endocrinology at William Beaumont Hospital in Royal Oak, Mich., says the procedure and related operations are still experimental. "I think it's kind of an exciting next step in our attempts to find a way for women who may have cancers in their reproductive years to still preserve their fertility," says Keye, president-elect of the American Society of Reproductive Medicine.
Every year up to 50,000 American women of childbearing age undergo cancer therapies that strip them of the ability to conceive.
Hundreds of women in North America and elsewhere have had their ovarian tissue frozen while they undergo sterilizing treatment for cancer and other conditions, but only a handful have used that tissue for eggs.
Scientists have shown that they can graft egg-producing ovarian tissue onto the pelvic wall of infertile women, but harvesting eggs from that site is more difficult than the forearm, which also is easier to monitor for egg development. Operating on the arm also is somewhat less complicated.
In the latest study, Dr. Kutluk Oktay, an infertility specialist at Cornell University's Weill Medical College in New York City, and his colleagues transplanted small patches of autologous, or self-donated, ovary tissue onto a forearm of each woman before each underwent treatment that ended their ability to produce eggs.
Both patients were soon able to produce eggs -- one spontaneously, the other with the aid of hormone supplements -- from the grafts. The researchers detected the eggs with ultrasound and hormone tests. One woman sought to fertilize one of her eggs but the attempt failed. The other has decided to delay conception, Oktay says.
The graft sites are on the soft area of the arm, about two inches toward the hand from the elbow, and have so far proved to be quite durable. But Oktay says the transplanted ovaries may be vulnerable to high temperature.
Oktay, who previously reported on the patient with cervical cancer, says he has applied for funding to conduct a long-term study to include up to 40 women. Many, but not all, will be cancer patients. "A lot are young and don't want children right now." The rest are likely to have other diseases including lupus, sickle cell anemia and some cases of endometriosis, that require sterilizing therapy.
Roger Gosden, a McGill University gynecologist who pioneered menopause reversal, says that while scientists have essentially solved the technical hurdles to the transplant procedure, safety questions remain.
Although studies suggest the technique is safe for women with Hodgkin's disease, the same can't yet be said for those with breast cancer, leukemia and other diseases. Some experiments with mice suggest that it may be possible to re-seed a woman with cancer that has lingered in her ovarian tissue, although other evidence refutes those results.
In addition, Gosden says there may be hosting problems associated with the procedures. Some researchers have wondered whether radiation therapy damages the reproductive tract in ways that make conception and pregnancy difficult. However, with chemotherapy "the effects appear to be reversible," he says.