Swedish scientists have successfully transplanted uteruses in sheep, an achievement that paves the way for women who do not have a womb to bear their own children. The team, based at the Sahlgrenska Academy at Goteborg University, presented the findings at the annual conference of the European Society of Human Reproduction and Embryology (ESHRE) in Prague, Czech Republic. The work follows the group's previous successes with mice, reported three years ago.
In 2003, the researchers transplanted uteruses into 12 mice that were 99 per cent genetically identical to the donors, placing them alongside their existing uteruses in order to compare them. They then implanted embryos into the wombs, and several pups were born as a result. However, when they tried to repeat the procedure with transplants between animals that were not genetically matched, the wombs were rejected.
In the latest research, team leader Dr Mats Brannstrom and his colleagues removed wombs from sheep, and replaced them several hours later. They showed that the organs still worked properly 2-3 months after the transplant operation. Brannstrom says the next step is to try and get the animals pregnant, and then to attempt transplanting a uterus from one sheep to another, using immunosuppressant drugs to prevent rejection. He then wants to test the procedure in primates, and hopes that human womb transplants will be possible in five years time. 'It's not a life-saving operation, its about improving quality of life, so we have to be sure it's a safe procedure', he told Nature News.
If they can be successfully carried out in humans, uterus transplants could help women who were born without a womb, or those who have lost their womb following surgery - to treat cervical cancer, for example. A womb transplant would have several advantages over surrogacy, according to Brannstrom: 'If you put your embryo in another woman you give up control and you don't know if she might be smoking or taking drugs'. He says that the best donors for womb transplants would be older sisters or mothers, to minimise the chances of rejection. The womb could be removed after having children, so that the recipient did not have to take immunosuppressant drugs for life.