Temporary womb transplants?

Wow – not sure what to think about this:

Nine women in Sweden have successfully received transplanted wombs donated from relatives and will soon try to become pregnant, the doctor in charge of the pioneering project has revealed.

The women were born without a uterus or had it removed because of cervical cancer. Most are in their 30s and are part of the first major experiment to test whether it’s possible to transplant wombs into women so they can give birth to their own children.

The intended procedure, as it stands now, is not ethical by Catholic standards:

The transplant operations did not connect the women’s uteruses to their fallopian tubes, so they are unable to get pregnant naturally. But all who received a womb have their own ovaries and can make eggs. Before the operation, they had some removed to create embryos through in-vitro fertilization. The embryos were then frozen and doctors plan to transfer them into the new wombs, allowing the women to carry their own biological children.

But what if doctors eventually learn how to connect a transplanted uterus to fallopian tubes, to permit for natural conception?  Could the procedure then be ethical?  It’s not surrogacy.

At first I thought, “Well, a uterus is just an organ, and other organs can be transplanted ethically.”  But it’s not really just another organ, because its purpose is to support another human being; whereas if you undergo a risky heart transplant, it’s only your own life you have to consider.  So far, no one with a transplanted womb has brought a baby to term. Is it ethical to get pregnant when you have reason to believe the baby may not survive? If so, is that different from a woman with the womb she was born with, knowingly getting pregnant even if she’s had several miscarriages before?

Also, who could ethically donate a womb, according to Catholic bioethics?  I’m pretty sure it would not be ethical for a married woman of childbearing age to donate her womb, even if she considered herself “done” having children.  What about someone who made a vow of celibacy? A purely medical question:  would a post-menopausal woman’s womb even be useful to a young woman with younger eggs who was trying to conceive?

Does it make a difference that these are intended to be temporary transplants?  The idea is that women try to have as many as two children, and then the uterus is removed so they can stop taking anti-rejection drugs, which have bad side effects.

I don’t want to automatically shy away from science. Just because something sounds creepy doesn’t mean it’s wrong.  But this is an especially complicated situation.  What do you think?