A Swedish woman may soon become the first person ever to carry a baby in the very womb from which she was born. Sara Ottosson, a 25-year-old who, like 1 in 5,000 women, was born without a uterus, has been shortlisted for an experimental uterus transplant surgery. Sara's would-be womb donor is Eva Ottosson, her mother.
"I've had two daughters, so it's served me well," Eva Ottosson told the press, referring to her uterus. "[Sara] needs it more than me."
Sara, like all women whose wombs are missing, dysfunctional or were cancerous and had to be removed at a young age, cannot naturally conceive and give birth to a child. Like many others, Sara is so desperate to do so that she has volunteered for a completely unproven surgery — one that has never before worked in humans — in which her mother's uterus will be transplanted into her abdomen. It will then be implanted with one of Sara's own eggs, fertilized in vitro. After delivering the baby nine months later, Sara will go back under the knife to have the borrowed uterus removed.
A previous attempt at uterus transplantation was made in 2000 in Saudi Arabia, but the recipient's body rejected the foreign organ, and it had to be removed four months into her pregnancy. Now, a team led by Mats Brannstrom, a Swedish surgeon, thinks that enough research has since been done to try the procedure again. Sara hopes the team will choose her for their first attempt.
Edwin Ramirez, a gynecologist at Antelope Valley Hospital in Lancaster, Cali., who leads a group that also hopes to transplant a uterus within the next two years, told Life's Little Mysteries what makes the surgery so unique, and why a mother-daughter donor-recipient team provides the best shot for pulling it off.
Will it work?
"A uterus transplant is complex in the sense that the pelvis is more vascular than other parts of the body — it has more blood vessels — so the risk of bleeding during uterus removal is higher than with other organs," Ramirez said. He and his colleagues are developing a protocol for the organ removal procedure by operating on sheep and monkeys.
Another issue is organ rejection: When you receive an organ transplant, your immune system treats the foreign organ as an invading enemy and tries to break it down. Organ recipients must stay on a regimen of "immunosuppressive" drugs for the rest of their lives to stifle this natural response. Sometimes, though, the drugs don't work — and they didn't work for the patient involved in the previous uterus transplant attempt.
Furthermore, immunosuppressive drugs have side effects (such as weakening the immune system's response to real infections and illnesses) which could be dangerous to both mother and fetus during pregnancy. An appropriate drug regimen thus needs to be designed specifically for uterus transplantation recipients.
Despite these complications, uterus transplantation is less complex overall than heart or liver transplantation, Ramirez noted; the procedure has simply been slower to develop because it isn't life-saving. "It's a little different than your traditional organ transplantation because we're dealing with a nonvital organ. It's more of a life-improving procedure," he said. [Read: Uterus Transplant: Q&A with Surgeon's Collaborator]
World's best mom
The mother of the recipient makes the ideal donor, Ramirez explained. The mother of an adult daughter is most likely in her late 50s or early 60s, past menopause, and is no longer in need of her uterus. "You're performing an operation on a female that really doesn't need to have her uterus removed, but she's doing it to benefit her daughter," he said.
Old age is no issue when it comes to the uterus: It can be brought back to full functionality at any point. "The uterus will always be functioning. If you give it estrogen, it's going to respond. If you prepare the uterus, it should work perfectly fine in the recipient," Ramirez said.
Only a mother-daughter pair who share the same blood type would be considered for surgery, Ramirez explained, because this lowers the chance of organ rejection. Having 50 percent of the same genes also means the mother-daughter pair might share similarly positioned blood vessels, he said, making it easier for surgeons to lock the transplanted organ into place in the daughter.
In short, he said, "If we can transplant a uterus into the recipient who actually was born out of that uterus there's less chance of rejection."
Ramirez and Brannstrom are colleagues who have worked together on uterus transplantation research in the past, Ramirez said, but now they lead separate teams, both of which would like to be the first to transplant a womb.
"From a personal standpoint, I feel that I know Brannstrom fairly well and I think he's making this public because he sees that our group is advancing fast," Ramirez said. "He doesn't want to be behind in research."
Ramirez said Brannstrom may well be ready to do the surgery within a year, but that his group is nearly ready, too. "We already have our patients screened and ready to go. Do I feel like I can do it tomorrow? Yes. But I'm a perfectionist," Ramirez said.
Brannstrom could not be reached for comment.
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Natalie Wolchover was a staff writer for Live Science from 2010 to 2012 and is currently a senior physics writer and editor for Quanta Magazine. She holds a bachelor's degree in physics from Tufts University and has studied physics at the University of California, Berkeley. Along with the staff of Quanta, Wolchover won the 2022 Pulitzer Prize for explanatory writing for her work on the building of the James Webb Space Telescope. Her work has also appeared in the The Best American Science and Nature Writing and The Best Writing on Mathematics, Nature, The New Yorker and Popular Science. She was the 2016 winner of the Evert Clark/Seth Payne Award, an annual prize for young science journalists, as well as the winner of the 2017 Science Communication Award for the American Institute of Physics.