St. Louis ? When Joy Lagos learned she had cancer, she was confident she would beat it. What brought the San Francisco resident to tears, however, was knowing that radiation and chemotherapy would lead to early menopause and rob her of the chance to have children.

Last week, that may have changed.

A renowned infertility expert in suburban St. Louis transplanted a whole ovary from Lagos’ sister into Lagos, a step that could enable her to have children. Dr. Sherman Silber completed the transplant Feb. 5, after performing the same procedure between twins last month.

The operations are believed to be the first whole-ovary transplants done in the United States. Surgeons in China reported a successful transplant earlier this decade, but offered scant details.

The surgery could restore normal hormone function for women going through early menopause, whether because of cancer treatments or other, unexplained causes. It also could mean that one day, a woman with cancer could freeze an ovary, undergo chemotherapy and radiation, and have her own ovary returned later to restore her fertility.

Lagos, 30, is now waiting to see whether the transplant takes hold and allows her to ovulate normally, and whether she can get pregnant. The twins also are waiting to learn the outcome of their operation.

Seeking motherhood

When Lagos was diagnosed with non-Hodgkin’s lymphoma in 2004, her older sister Maeapple Chaney, now 31, donated bone marrow. Lagos was cured of cancer, but the treatment disabled her ovaries and she went into early menopause.

“I was devastated,” Lagos recalled, her voice breaking as she tried to talk about it Monday. Now married, Lagos was not with a partner at the time, and so was not able to freeze any embryos, she said.

After the cancer treatment, she wanted to have children of her own. But the menopause also induced osteoporosis, diminished her sex drive and interfered with the natural “ebb and flow” of her emotions, she said.

“I think it sounds selfish, but I just wanted to feel like a woman again,” she said.

Chaney was willing to donate eggs so that Lagos and her husband, Rodrigo Lagos, could have a baby through in vitro fertilization, but then Rodrigo Lagos saw a TV report about Silber.

In 2004, Silber placed strips of ovarian tissue from a fertile twin into her prematurely menopausal sister. That woman, Stephanie Yarber, has since given birth to two children. The doctor has done similar surgeries on six other sets of twins, all of them involving transplants of ovarian tissue, not whole ovaries.

All of the twins who have had the ovarian tissue transplants are ovulating and menstruating normally, Silber said. But the women may get only a few years of ovarian function using the strips of tissue, he said.

Promising work

Silber, who directs the Infertility Center of St. Louis at St. Luke’s Hospital in Chesterfield, Mo., hopes that a whole ovary with its own blood supply will last decades.

Last week, Silber removed one of Chaney’s ovaries and gave it to Lagos, employing a form of microsurgery that requires sewing the donor’s tiny ovarian artery to the ovarian artery of the recipient.

“It’s maybe the size of a tiny piece of white thread you might use to sew on a button,” Silber said of the vessel.

Dr. Pasquale Patrizio, director of the fertility center at Yale University, said he is watching Silber’s work because he is working on freezing and thawing ovaries to help cancer patients preserve their fertility.

“It’ll tell us in the field if the entire organ can be successfully retransplanted,” Patrizio said.

Silber said the surgery also could be a help one day for women who do not have cancer. He said about 1 percent of women naturally experience premature ovarian failure, which leads to early menopause.

Because Lagos and her sister are closely matched biologically, Lagos does not need immune-suppressing drugs to prevent organ rejection. In other cases, though, doctors worry what those drugs could do to the mothers-to-be and their babies.

“If they’re not a close match, we’re not ready to tackle that yet,” Silber said.

The Lagoses said the surgery cost about $15,000. Chaney, who lives on Vandenberg Air Force Base in Lompoc, Calif., said it is possible she could go into menopause a few years earlier than she otherwise would have because of the ovary donation, but she does not regret the bone marrow and ovary she has given her sister.

“It’s a great opportunity, both for my sister and for fertility treatment in general,” Chaney said.