Two Swedish women are carrying the wombs of their mothers after what doctors called the world's first mother-to-daughter uterus transplants.

Specialists at the University of Gothenburg completed the surgery on Sept. 15-16 without complications, but say they won't consider the procedures successful unless the women achieve pregnancy after their observation period ends a year from now.

An in vitro fertilization procedure may be used to help a women conceive if she's had her uterus removed due to cervical cancer.An in vitro fertilization procedure may be used to help a women conceive if she's had her uterus removed due to cervical cancer. (Kacper Pempel/Reuters)

"We are not going to call it a complete success until this results in children," said Michael Olausson, one of the Swedish surgeons told The Associated Press. "That's the best proof."

He said the women started in-vitro fertilization before the surgery. Their frozen embryos will be thawed and transferred if the women are in good health after the observation period, Olausson said.

The university said one recipient had her uterus removed many years ago due to cervical cancer and the other was born without a uterus. Both women are in their 30s.

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

Turkish doctors last year said they performed the first successful uterus transplant, giving a womb from a deceased donor to a young woman. Olausson said that woman was doing fine but wasn't sure whether she had started undergoing fertility treatment yet.

In 2000, doctors in Saudi Arabia transplanted a uterus from a live donor, but it had to be removed three months later because of a blood clot.