First U.S. Uterus Transplant Planned

An embryo created through in vitro fertilization would then be placed in the womb. If the pregnancy goes well, the baby would be delivered by Caesarean section to minimize risks from labor and to allow doctors to simultaneously remove the uterus, so the woman could discontinue the anti-rejection drugs.

"We are calling it a temporary transplant," Del Priore said. "This minimizes the time patients have to be on the medications and makes it a much more reasonable risk to take to have a baby."

If it works, in subsequent cases women with functioning ovaries who got a uterine transplant might eventually be able to get pregnant without IVF, Stega said.

But other experts called for further work on animals first, including showing that a primate could bear offspring with a transplanted uterus.

"I think we should do more animal research before we do it in a human," said Mats Braennstroem of Goeteborg University in Sweden, who has been trying the procedure on mice, pigs and sheep. "We have to be sure it's a safe procedure and that we know exactly how we would do it in humans. We haven't done all those experiments yet."

But even if animal work showed the procedure could succeed, some questioned whether it is ethical to subject a woman to the risks of major surgery -- and both mother and baby to powerful anti-rejection drugs -- for a condition that is not life-threatening.

"This is not like a kidney transplant -- it's not medically necessary to the woman's life," Andrews said. "Without it, the woman can live a healthy life. She still has options. She can adopt. She can even still have her own biologic child with a surrogate."

And while women who have undergone other types of transplants have given birth to healthy babies, it is risky to subject developing fetuses to anti-rejection drugs and to a possibly inhospitable uterus.

"This is a very complex surgery with a lot of risks, both known and unknown, to both the women and the child," said Tommaso Falcone, a fertility specialist studying ovarian tissue transplants at the Cleveland Clinic. "I'd want to see a good core of animal data before risking it."

"You might have a viable fetus, but as it outgrows the blood supply you might end up with a compromised fetus," said John Fung, a Cleveland Clinic transplant surgeon.

Del Priore acknowledged the possible risks, but he and others said women should have the choice.

"For many women, it is an essential part of their life to be able to carry their own child. They are willing to do many brave things to do it. Natural childbirth can be very risky, but women choose that in many parts of the world. I do not think this is in any sense reckless when you compare this to that," Del Priore said. "I wish everyone could be happy with an adoption. But there are many people who don't think that is the right choice for them."

Although it may seem like the stuff of science fiction, and many obstacles remain, some even wonder whether the procedure, if successful, could theoretically lead to men being able to bear children.

"If they perfect this procedure, trust me, somebody else will think it's a good idea," Murray said. "If gay marriage gets some people upset, this is going to tip a lot of people over the edge."