A woman who became pregnant after her identical twin donated ovarian tissue has spoken about her joy at becoming the mother of a health baby girl.
Stephanie displays a photo of her baby
Stephanie Yarber went through a very early menopause at the age of 14, but her identical twin sister - Melanie Morgan - did not.
Baby Anna Grace is thought to be the first to be born after the transplantation of ovarian tissue from one person to another.
Stephanie said she had been concerned she would not be able to be a mother.
"I had my doubts, but I knew that we were going to do everything we could.
"So was Melanie. We wouldn't give up."
Her sister added: "She wanted kids, and I had the ovary. I'm just so glad it worked."
The ovary tissue transplant was carried out at St Luke's Hospital in St Louis in April last year.
Soon after the procedure was completed, Stephanie, who was infertile, started having periods.
Melanie, who already had three children wanted to donate her eggs so her sister could also become a mother.
But this did not work, so she donated some tissue from her healthy ovaries instead.
In a five-hour operation last year at St Luke's Hospital in St Louis, doctors removed the ovary, and separated off the outer tissue that contains the egg-producing follicles.
They then grafted a third of this tissue on to each of Mrs Yarber's ovaries, while the final third was kept back in case the initial transplants did not work.
The risk of organ rejection was minimal because identical twins have the same genes increasing the chances of success.
Dr Sherman Silber and colleagues who carried out the operation said although ovarian transplantation between identical twins would be rare, the technique had great potential for many women.
Dr Adrian Lower, a fertility specialist in the UK who said is treating twins in the same situation, said he would consider attempting the same procedure.