Uterus transplants have been in the news a lot lately, in ways that suggest they will someday be commonplace. Will they? Should they?
The idea of transplanting a uterus is quite new. The first serious basic research began only twenty years ago. The first attempt in humans happened a year later. But things moved quickly. In 2014, the first baby gestated in a transplanted uterus was born. (See timeline below)
The pocket narrative goes something like this. A uterus is surgically removed from one woman's body and placed into another woman's body. The first woman doesn't need it anymore; the second woman will use it to grow her children and have the authentic experience of pregnancy.
But important details are sometimes glossed over, or left out entirely. Allow me to touch on three.
Uterus transplantation involves a lot of medical intervention and surgery. There is the surgery to remove the uterus from the donor. The Swedish team led by Mats Brännström at the University of Gothenburg, who ran an observational trial in nine women, reported that donor women underwent surgery that lasted between 10 and 13 hours and involved hospital stays of six days. Another surgery is required to transplant the uterus into the recipient woman; these took between 4 and 6 hours and involved hospital stays of six to nine days. (Uterus transplant surgeries are now quicker, but they will always be fairly long and complicated procedures requiring significant recovery.)
Prior to undergoing the transplant, the recipient woman will have to go through egg retrieval and IVF. During the year or so following the transplant, while doctors watch for signs of organ rejection, she will have to have regular examinations and cervical biopsies. If all goes well, after about a year, she will have an embryo transfer.
Her baby will be born via another surgery, C-section. And, after she is done having children, she has to have another surgery — to remove the donated uterus. That's right, even if the uterus performs exactly as hoped, it has to be surgically removed as soon as possible. Why? Because immunosuppressant drugs.
Organ transplant requires the recipient to take immunosuppressant drugs to prevent rejection. The body senses the organ is foreign and will attack it if the immune system is not dialled back. Immunosuppressant drugs can have side effects like nausea, diarrhea, hair loss, hair growth, high blood sugar, loss of bone mass, and increased risk of infection. It is because of these undesirable effects that doctors remove the uterus once it's no longer needed.
Some people argue that, while the trade-off is clear for transplants that are life-saving, like heart or liver or lung, transplant is less clearly justified for pregnancy, especially when there are alternatives like surrogacy and adoption.
The drugs may also affect the babies. Fetuses exposed to immunosuppressant drugs in utero may be at greater risk of intrauterine growth restriction, pre-term birth, and low birth weight.
So far, the costs of uterus transplants have been covered by research budgets, since the transplants are considered experimental. But if this were a treatment a woman had to finance privately, it would be pricey: multiple complex surgeries on two people; intensive year-long medical follow-up; drugs; IVF; birth; and the increased chance of time in the neonatal intensive care unit. No one knows what the total tab might come to, but TIME magazine estimated that in the US, it could ring in at around half a million dollars.
To its credit, the International Society of Uterus Transplantation launched an international registry to follow donor, recipient and offspring outcomes. This is good. Increasingly, however, it's starting to look like the end goal may not be person-to-person transplant at all. The same scientists who pioneered uterus transplants as we know them today are also at work on developing uteruses bioengineered from a woman's own stem cells.
If workable, this could solve several problems. Most importantly, it would mean no surgical risk to donors. Also, since the uterus would be manufactured from a person's own cells, it shouldn't face rejection, so the recipient woman wouldn't have to take immunosuppressant drugs. The baby wouldn't be exposed to them either. It could also increase the supply of uteruses. And it might mean the uterus doesn't need to be surgically removed after use. Building and surgically implanting a bespoke uterus will not be cheap, but it could prove much safer all round.
Brännström is enthusiastic. He predicts that, like the live transplant project, it could take a decade to move it from lab to clinic. Mark your calendars.
A short history of uterus transplantation
1999 - Animal research on uterus transplantation begins in Sweden. Over the course of the next decade, uterus transplants are studied in mice, rats, sheep, pigs, baboons and cynomolgus macaques. The studies also develop protocols for suppressing rejection.
2000 - First attempt at transplanting a human uterus takes place in Saudi Arabia. The organ comes from a live, 46-year-old, premenopausal donor. The recipient, who underwent a hysterectomy six years prior, is 26 years old. The woman does not resume spontaneous menstruation, and 99 days after the surgery, the uterus has to be removed because of lack of blood supply.
2003 - First ever offspring born after uterus transplant -- in a mouse -- in Sweden. The donor and recipient are immunologically so similar that rejection is not a concern. The offspring appear normal.
2011 - Second attempt at transplanting a human uterus takes place in Turkey. The uterus comes from a 22-year-old deceased donor. The recipient is 21-year-old woman born without a uterus. The recipient resumes menstruation, but multiple embryo transfers over four years result in no pregnancies.
2013 - A human trial involving nine women begins in Sweden. Eight of the recipient women were born without a uterus; one had a hysterectomy. The donors include five mothers and a sister, maternal aunt, mother-in-law and close friend. Two of the transplants have to be removed early: one at day 3 and the other at month 3.5. Of the remaining seven, all show spontaneous menstruation around month 1 or 2. Embryo transfer takes place 12 to 14 months after transplant.
2014 - First-ever human birth after uterus transplantation, in Sweden. The donor is a 61-year-old woman who'd had two children; the recipient is a 35-year-old woman born without a uterus; the two are friends. (The recipient had three episodes of rejection, one of which was during the pregnancy; all were successfully reversed. Just before week 32 of the pregnancy, the woman developed pre-eclampsia and had to deliver.)
2017 - First birth after deceased donor transplant, in Brazil. The donor is a 45-year-old woman who died of a brain hemorrhage; the recipient is a 32-year-old woman born without a uterus. The transplanted uterus is removed during the C-section birth.
2019 - First birth after robot-assisted uterus transplantation, in Sweden. The donor uterus is removed using minimally-invasive surgery.
Worldwide, at least 15 babies have now been born following uterus transplantation: nine in Sweden, two in the United States, and one each in Brazil, Serbia, India and China.
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