The science that brought you heart transplants, kidney transplants, and even lung transplants, is at it again -with a vengeance. Well, maybe I shouldn’t word it that strongly -I’m sure the folks that thought this one up assumed they were doing some good. And maybe they are… I mean, Science is good, right?
I’ve always believed that the world is filled with answers just waiting for the right questions. If there’s a problem, grab an answer, then look around for the appropriate question; you might get lucky. That’s how it used to be done… Too random? Well then create a problem nobody’s thought of. Then solve it. I can think of several transplant problems one might want to create and then solve. It might make sense to attempt to transplant bowels, for example -you never know when a new set might come in handy. Or how about eyes? They’re useful… And then there is always somebody looking for a new pair of ovaries. For that matter, limbs would be big -entire limbs, not just their parts. Tongues..? The list goes on. But a uterus? http://www.bbc.co.uk/news/health-25716446
I have to admit I am conflicted on this issue. On the one hand, it would seem natural for a woman without one to want one -a uterus does all sorts of important stuff: carrying babies springs immediately to mind. But hold on. A uterus placed in someone else’s body is in a foreign country. It is a stranger at a family party and after being roundly embarrassed and then exposed as someone they don’t know, it is immediately rejected and shown the door. Explanations just don’t work under those circumstances without drugging the entire family into submission. And don’t forget, the uterus doesn’t merely show up because it got the wrong address; it was likely recruited for a specific and important job. No one orders a new one just to re-create the painful periods of their youth, nor in order to keep a ready supply of fibroids on hand.
No. Odds on, it will be recruited as a biological isolette. An incubator. But fetuses are notoriously sensitive to chemicals as they are developing and so what keeps the incubator alive and well, had better have a similar effect on the incubee. And the only way to keep the body from destroying the transplanted uterus is with anti-rejection drugs -immune-suppressors- which are toxic. Swords of Damocles.
Obviously a similar situation obtains with a transplanted kidney going through pregnancy -it needs immune suppression, too. But although the demands on kidney function change with the constantly moving target of pregnancy requirements, one might argue that there are some fundamental differences that separate kidney function from uterine function in a pregnancy.
First, there is the obvious need for a fertilized egg to actually implant itself in the wall of the stranger -this is the bond that ultimately creates the placenta which in turn nourishes the developing fetus. I can’t imagine this is easy at the best of times. So, the uterine muscle must have a smoothly functioning mechanism to allow an attachment that is not impeded by any inflammatory response from the immune system, or inhibitory effect by the drugs. It has to be a strong and functional union because that union will have to allow for the growth and changing metabolic and nourishment needs dictated by it’s totally dependent passenger for the entire pregnancy: a Gordian knot…
That uterus will also have to grow as the baby grows inside it. Grow -not merely stretch. Too much stretching without concomitant growth might irritate the muscle fibers and cause them to do what muscles all over the world have been taught to do under the circumstances: contract. In obstetrical terms, this is sometimes known as labour… Admittedly, hormones from the placenta and who knows where else will normally have a role to play in keeping the uterus relaxed and quiet -coordinating things. But a transplanted uterus, already confused by its new digs and having to contend with a whole bagful of noxious chemicals may well react differently: like an already rebellious teenager in a new and (maybe) abusive foster-home… (Uhmm, okay that metaphor was probably a bit of a stretch as well…)
And if the pregnancy actually succeeded and made it to an acceptable state of viability for the baby, a Caesarian section would be necessary -I can’t see the uterus cooperating sufficiently to agree to any kind of productive and efficient labour. That’s fine, of course: under the circumstances a Caesarian delivery would likely be the safer option. Perhaps even a Caesarian hysterectomy, because I suspect the uterus would only be a single use entity after what it would have been through and so require removal anyway.
So, what am I saying? I suppose the first thing is that I congratulate the surgical teams for their success in many of the transplants so far and I wish them and the recipients the best of luck. It was inevitable that someone would try it some time, I guess. But remember, successful transplant does not necessarily imply successful function. I have to admit that it is a procedure I will watch with much interest, but from the corner of the room. If all goes well, it will surely be a boon for those women who have lost their uteri through surgery or disease, or even in the genetic lottery that occasionally intervenes so tragically in some lives. Until now, I suppose, adoption would have been the only option, but I understand the wish to gestate one’s own baby with one’s own eggs and in one’s own body.
Maybe, someday, uterine transplants will be viewed much like heart transplants… and yet they are not. Let us not forget that unlike hearts or kidneys, unlike lungs or livers that are transplanted only in extremis and when all other less drastic options have failed, with uterine transplants, survival of the recipient without the organ is not at stake; survival of the baby in utero is, however. And it’s not just survival, we’re aiming for either… It’s the healthy survival of an initially normal fetus that has developed and grown in an abnormal environment. Heaven only knows, enough can go wrong in a normal uterus -even with the best of care- let alone one stitched in place and clothed in chemical soup.
Perhaps I’m viewing this as an elder who has seen many promising ideas go badly wrong -think, for example of thalidomide and the developmental anomalies it produced in fetuses. Or DES for threatened miscarriages that resulted, among other things, in clear cell carcinoma of the vagina. So my advice is one of caution. Just because we can do it, doesn’t mandate that it must be done… Should be done. Ideas come and go -that’s what they’re for after all; it’s how we make progress. Improve things… But in this case, the results may influence -even malign- future generations; the results may be future generations. Let’s get it right -we’re not just dealing with kidneys here.