Four women who had womb transplants have had embryos transferred in an attempt to become pregnant.
If any of the embryos implant, this could lead to the first live birth following a womb transplant. The recipients have functioning ovaries, so their own egg cells were used in IVF before being transferred into the wombs that were donated by living relatives.
'We have already begun transferring embryos into four of the women and plan to make attempts with the others when they are ready', said Professor Mats Brännström at the University of Gothenburg, Sweden, who is leading the trial. 'One or two more will perhaps get pregnant and miscarry, and one or two won't be able to get pregnant', he told Associated Press.
The first of these embryo transfers was reported last month (in BioNews 740); however, Professor Brännström has not yet confirmed whether it led to pregnancy.
Professor Brännström's team has performed uterus transplants on nine women as part of this trial, which began in 2012. Two women have since had to have their transplanted wombs removed: one due to an untreatable infection, and other due to blood clots in the transplanted blood vessels.
'The women who had to have their transplanted wombs removed were of course very disappointed, but both of them have recovered well', said Professor Brännström.
Four of the women also had 'mild cases of transplant rejection', but according to Brännström, 'after six months, the immunosuppression could be reduced to relatively low levels'.
Dr Yacoub Khalaf from Guy's and St Thomas' Hospitals commented on the trial, telling Associated Press: 'We really don't know if the blood flow to the uterus will increase and adapt in the same way as in a regular pregnancy. A live birth will be the best validation that this works'.
Professor Charles Kingsland from Liverpool Women's Hospital also commented: 'There are questions about how the physiological changes in the uterus will affect the mother and whether the transplanted uterus will be conducive to a growing baby'.