MILWAUKEE, Wisconsin (AP) -- A New York hospital is taking steps to offer the first uterus transplant in the United States, a radical experiment that might allow women whose wombs were removed or are defective to bear children.

The wombs would come from dead donors, just as most other organs for transplants do, and would be removed after the recipient gives birth so she would not need anti-rejection drugs her whole life.

The hospital's ethics board has conditionally approved the plans, although the hospital's president warned women not to get false hopes because a transplant is not expected "any time in the near future."

However, several experts cautioned that much more research needs to be done before the procedure is actually attempted on a woman.

The New York doctors just did a six-month trial run, showing that wombs could be obtained from organ donors, and now are screening potential recipients.

"I believe it's technically possible to do," said lead physician Dr. Giuseppe Del Priore.

However, even some scientists involved think they should produce more healthy offspring in animals before trying the procedure on women.

Others note that about a thousand women already have become pregnant after kidney, heart and other transplants, with generally good results. They view uterus transplants as a way to help women whose only option now for a biological child is through a surrogate mother.

"If this is a passionate desire for a woman who's had surgical removal of a uterus, I would think this would be something she'd really want to pursue," although the risks would have to be carefully weighed, said Julia Rowland, director of the National Cancer Institute's Office of Cancer Survivorship.

The transplant project is being led by Del Priore, a cancer specialist, and Dr. Jeanetta Stega, a gynecologic surgeon, at the New York Downtown Hospital, part of the New York-Presbyterian Health Care system.

Transplants for quality of life
Organ transplants usually are performed to save lives, but increasingly they are being done to improve quality of life. Hand transplants and the recent partial face transplant of a woman in France are examples.

Besides surgical complications that can prove fatal, the main risk in such operations is the need for lifelong immune-suppressing drugs to prevent organ rejection.

However, if a uterus had to be removed, it would be serious but probably not life-threatening like the loss of a liver or heart, proponents say.

A uterus transplant has only been attempted once -- in Saudi Arabia in 2000. That womb came from a live donor and had to be removed three months later because of a blood clot. Stega thinks that transplanting more blood vessels and using better anti-clotting drugs would lessen this risk.

Doctors in London and Hungary want to offer such transplants and several are working with Del Priore and Stega. Potential candidates include women born without a uterus, those with abnormal tissue growth called endometriosis, and women who lost a womb to non-cancerous tumors called fibroids.

Del Priore is interested in fertility preservation for cancer survivors.

"Patients ask, 'Can anything else be done?"' he said.

Margaret Cieprisz was one. The Manhattan woman was diagnosed with ovarian cancer at age 38, a few months after she was married.

"The fact that I wasn't going to be able to have children, it was an unbearable thought to have to accept," she said.

She delayed a hysterectomy to create embryos that later were implanted in her sister, who became a surrogate mom for her 2 1/2-year-old daughter, Natalie. If a uterus transplant were possible, "I would have wanted to consider it," she said. "I'm so happy that I have a child, but I kind of missed out on something."

To be transplant candidates, women must have frozen embryos so there is no fertility issue complicating the chances of success, Del Priore said.

Anti-rejection drugs generally are not dangerous to a fetus although certain ones should be avoided, said Dr. Vincent Armenti, kidney transplant chief at Temple University School of Medicine in Philadelphia. He keeps a registry of pregnancies in transplant recipients throughout North America.

As of mid-2005, 990 transplant recipients had had 1,547 pregnancies with results not much worse than for the general population. Of the 772 pregnancies in kidney recipients, 590 births resulted (the rest miscarried or chose abortion). About half of the babies were born prematurely -- most only slightly -- and much of this was due to the mothers' high blood pressure, not the transplant.

But some experts are wary.

More research urged
"I think we have to learn quite a few things" before proceeding, said Stefan Schlatt, a researcher at the University of Pittsburgh, where a failed uterus transplant recently was done in a Rhesus monkey. Scientists are preparing to try again. Others have been done in mice, rats, rabbits and pigs, with offspring only in rodents.

"The whole thing is complicated. I think it's not really ready for prime time," said Dr. James Grifo, an infertility expert at New York University, who gave Del Priore a grant for rat research years ago.

The president of Del Priore's hospital, Dr. Bruce Logan, called the research "exciting and promising," but warned: "Every step in this long research process must be handled in a measured, prudent manner. Our first concern is always the safety of our patients."

The ethics board has approved the plans with the understanding it will reconsider once a patient is chosen.

"We want them to approve the actual patient, not just the process," Stega said.

The cost is unknown but could top $500,000, including two weeks of hospitalization, Del Priore said. He expects the cost to be shared by the hospital, charities that support infertility research, the patient, and insurers who cover the embryo creation part.