Two Swedish women now carry the wombs that gave birth to them after doctors completed the world's first mother-to-daughter uterus transplants, according to the Associated Press.
The surgery was performed over the weekend at the University of Goteborg without complications, but the doctors on the case said it would not be a complete success until the women were able to become pregnant.
"We are not going to call it a complete success until this results in children," Michael Olausson, one of the Swedish surgeons, told the AP. "That's the best proof."
The statement from the University of Goteborg said one of the women had her uterus removed after treatment for cervical cancer, and the other was born without one, according to Agence France Presse.
Mats Braennstroem, the leader of the research team, said, "The mothers who donated their uteruses are already up and walking and are going to be able to go home within a few days." He said the younger women would have to wait one year before attempting to get pregnant via in-vitro fertilization, according to AFP.
The AP said the women had already started IVF and embryos created from their eggs were frozen, waiting to be transferred to the women's wombs after a observation period.
More on GlobalPost: Three-parent babies could become legal in UK
Braennstroem also said the uteruses can be removed after the women have "up to two children" so they would be able to stop taking the immunosuppressant medication that enabled their bodies to accept the transplants.
Eight more women are scheduled to undergo the procedure in Sweden this fall and next spring.
The team, consisting of 20 scientists, doctors and specialists, has been working on the project since 1999, said the BBC.
Last year, Turkish doctors said they had successfully transplanted a uterus from a deceased donor into a young woman, the BBC noted. The first such womb transplant that was attempted with a live donor happened in Saudi Arabia in 2000, though the organ had to be removed later due to a blood clot.
More on GlobalPost: Superbug kills 7th person at Maryland hospital