Imma Perfetto
Cosmos science journalist
A decade on from the first live birth from a transplanted uterus, the procedures remain complex and difficult with the potential for significant complications for both the recipient and live donor.
So far there have been only 100 successful transplants resulting in 40 live births, including 2 in Australia.
Associate Professor Rebecca Deans, a fertility specialist and gynaecologist at the Royal Hospital for Women and the University of New South Wales, has treated patients born without a uterus for 20 years.
Deans leads a uterus transplant clinical trial at Sydney’s Royal Hospital which, with 3 successful transplants from living donors and 2 live births to date, is currently at its half-way point.
The congenital disorder is known as Mayer-Rokitansky-Küster-Hauser Syndrome, and it affects about 1 in 4,500 female live births.
“Other patients who may require uterus transplant are those who have lost their uterus due to cancer or have had a hysterectomy after having a baby,” Deans tells Cosmos.
In most cases these individuals have functional ovaries and fallopian tubes, so they can have genetically related children through in vitro fertilisation (IVF). Deans says that uterus transplantation offers these people another pathway to parenthood beyond surrogacy and adoption.
The first attempt at uterus transplantation was carried out in 2000, but it wasn’t until 2014 that the first live birth was achieved, in Sweden.
How do you transplant a uterus?
There is a lot of important work to be done before surgery is on the cards.
This includes pre-screening the donor and recipient to ensure they are both healthy enough to tolerate the psychological and physiological burdens of the procedure. The recipient must then go through IVF to create at least 5 embryos.
Uterus transplants are complex surgical procedures because the organ lies deep within the pelvis and shares blood vessels with other organs, such as the bladder and the ureters (the tube that connects the kidney to the bladder).
“It’s 8 hours plus surgery to retrieve the organ,” says Deans.
And, because the uterus isn’t a static organ – it expands from about the size of a pear to that of a watermelon and back again during pregnancy – it also requires a very good blood supply.
“A lot of the vascularity for the uterus is almost like little spirals, like a little spring that sits around it. As it grows it stretches out those blood vessels, because the growth of the blood vessels can’t keep up with the growth of the organ itself,” says Deans.
“When you take the organ out for transplant, it’s not just the uterus. It’s the uterus plus its branch of blood supply, almost like a root system coming off it on either side. And then you need to plug those into the great vessels that run from head to toe on the body.”
Are transplant pregnancies risky?
From the day of the surgery, the recipient must begin taking drugs to suppress the function of their immune system.
“The whole reason the organ can stay in place is because we’re giving drugs to trick the immune system to not reject the organ,” says Deans.
“At any time, the immune system can suddenly realise that there is foreign material. Then want to sort of attack the organ, if you like.
“The highest risk is right at the beginning after the transplant, and then you can start to taper to a more maintenance level of immunosuppression.”
The team carries out biopsies of the cervix and looks at the tissue under a microscope to determine whether early signs of rejection (inflammation) are present. At this point, they may increase immunosuppression to ensure rejection doesn’t occur.
At about the 2–3-month mark, they can then begin embryo transfers.
“The success is quite high. It sort of sits at about 50% plus of having a live birth at the end of it, which is higher than the general population for IVF,” says Deans.
This is because the procedure is currently only performed on young women who are otherwise fertile and have no other health issues.
“The pregnancies have got a higher risk of things like infection and miscarriage compared to the general population because, obviously, with the immunosuppression drugs the woman is more likely to pick up infections which then may affect the foetus or the uterus,” says Deans.
They monitor the patient throughout pregnancy and then, often, deliver the baby by caesarean.
“There’s no nerve supply that’s attached [to the uterus]. It’s purely blood supply. And so, you don’t feel the pain of labour,” explains Deans.
Recipients must then wait 12 months before undergoing further embryo transfers for a second pregnancy.
Are uterus transplants permanent?
People who receive permanent organ transplants, such as a heart or kidney, must remain on immunosuppressing drugs for the rest of their lives.
This comes with heightened risk of developing secondary cancers because the dampened immune system is less able to fight of infections that cause cancer and recognise and destroy abnormal cells that may become cancerous.
So, to ensure that uterus transplant recipients aren’t subjected to immunosuppression for too long, they undergo a hysterectomy as soon as possible – after 2 live births or within 5 years.
Two weeks ago, it was reported that Kirsty Bryant, the first Australian to give birth from a transplanted uterus, had undergone a hysterectomy after her body began rejecting the organ.
“She’s now had a hysterectomy because she has elected not to have a second child with her uterus,” says Deans.
“We were working her up to that, and we noticed that with the cervix biopsy she started to form some early signs of rejection.
“Whenever you have a pregnancy that can put you at a higher risk of rejection,” says Deans.
This is because the body detects the foreign material introduced when patients have a caesarean.
“That might upregulate the immune system and then it might have picked up that there’s something going on there,” says Deans.
The team could have treated the rejection and proceeded with embryo transfer. But Bryant, who is now a mother to 2 children, ultimately chose not to.
“It wasn’t a decision that was taken lightly, and we would have supported Kirsty through [whatever] decision she was willing to make,” says Deans.
Can you transplant a uterus from a deceased donor?
In 2018, Cosmos reported on the first baby to be born following a uterus transplant from a deceased person.
“There’s 2 people doing this big operation, of which only one person really derives a benefit,” says Deans.
“I think, ideally, we can improve the program so that it can be utilising a deceased donor. Because, ethically, it’s so much easier to justify.”
However, there are still problems associated with deceased donors, such as less donor screening and a delay in transplanting the organ into the recipient.
“An organ needs blood supply, which gives it oxygen. We talk about ‘ischemic time’ where if it’s had X number of hours without blood supply, then it might not survive that process,” says Deans.
The risk of a uterus not surviving transplantation, due to rejection or vascular complication, also jumps from 10-20% for live donors to 40-50% for deceased donors.
Of the 3 transplants remaining in their research protocol, Deans’ team aims to trial the use of either 1 or 2 uteruses sourced from deceased donors.
“If we can improve the outcomes of deceased [donation], I think would be a fantastic way to be able to offer this to women around Australia.”
The current clinical trial, which will end after 6 transplants, was made possible through fundraising through the Royal Hospital for Women Foundation.
“The future is whether this will be something funded by the Australian government, by Medicare,” says Deans.
