The world's first successful ovary transplant has been carried out on a monkey, scientists in the US have announced.
Millions of women with infertility problems could be given hope after researchers successfully implanted ovarian tissue into an infertile rhesus monkey and used one of the resulting eggs to produce a healthy test-tube baby.
If the technology can be adapted for humans it could be used to treat young women who become infertile after cancer treatment or older women who have been through the menopause, scientists from the Oregon National Primate Research centre said.
Researchers removed the ovaries from seven rhesus macaque monkeys, and re-implanted slices of the tissue into three sites - the kidney, the arm and the abdomen. In four cases the tissue secreted eggs, which were collected and fertilised in the lab. The embryos were transplanted back into the womb and one developed into a healthy baby monkey.
The breakthrough was announced at the American Society for Reproductive Medicine (ASRM) conference in San Antonio.
"It's a great step forward," said researcher Professor Nancy Klein.
"The technology could allow women to preserve fertility in cases where they are going to lose it prematurely - say in the case of women undergoing chemotherapy for cancer."