Story highlights The women lacked uteri because of cancer or birth defect

They will undergo embryo transfers in a year

The transplants are the culmination of years of research

Two Swedish women have received new wombs donated by their mothers in the first mother-to-daughter uterine transplants, officials said.

The first woman had her uterus removed years ago because of surgery for cervical cancer, according to the University of Gothenburg in Sweden. The second woman was born without a uterus. Neither woman was identified by the university.

The operations were conducted Saturday and Sunday at the university's Sahlgrenska Hospital, said Dr. Michael Olausson, surgeon and professor.

"So far, the procedures have been a success, but the final proof of success will be the birth of a healthy child," Olausson told CNN.

In vitro procedures were performed on both women -- who are in their 30s -- before the operations, said university spokesman Krister Svahn. Their harvested eggs were fertilized and the embryos frozen.

They will receive an embryo through embryo transfer in 12 months, meaning the earliest a child could be born would be in 21 months, officials said.

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The hospital said the transplants -- the result of more than a decade of Swedish and international research collaboration -- were completed without complications.

More than 10 surgeons, who trained together on the procedure for several years, took part in the surgery, said team leader Dr. Mats Brannstrom, professor of obstetrics and gynecology at the university and the hospital's chief physician.

"Both patients that received new uteri are doing fine, but are tired after surgery," he said in a hospital statement Tuesday. "The donating mothers are up and walking and will be discharged from the hospital within a few days."

The aim of the procedures is to allow more women who lack uteri to bear children, the hospital said. In Sweden alone, between 2,000 and 3,000 women of childbearing age cannot have children because they lack a uterus.

The operations were the first live-donor uterus transplants from mother to child, Olausson said.

A transplant using a live donor was attempted in 2000, but it was unsuccessful, he said. A second transplant, using a deceased donor, was performed last year in Turkey, but "so far we have not heard that the woman is pregnant."

In a video released by the hospital, Brannstrom said he first got the idea in 1998, when he removed the uterus of a young Australian woman who had cancer.

"I had to tell her that she would be cured from her cancer, but she could not become a mother because she does not have a uterus," he said.

The woman suggested transplanting a uterus from her own mother, he added.

After returning to Sweden in 1999, Brannstrom launched a research project on the issue. Researchers were able to bring about successful pregnancies in some animals using the procedure, and they believe chances of a successful human pregnancy are good.

"I think the best reward we can get ... is when we see a live baby being born from one of our patients," Brannstrom said.