An American man who was born female but who underwent gender realignment surgery and is now legally male has given birth to a baby girl.

34-year-old Thomas Beatie, from the state of Oregon, opted to keep female reproductive organs when he changed gender 10 years ago.

He decided to have fertility treatment and became pregnant by artificial insemination when it was found that his female partner was unable to have children.

The baby, conceived through artificial insemination using donor sperm and Mr Beatie's own eggs, was born on Sunday. Mr Beatie and the baby are 'healthy and doing well,' People magazine reported.

'The only thing different about me is that I can't breastfeed my baby. But a lot of mothers don't,' People quoted Mr Beatie as saying. He has had his breasts surgically removed.

He told the magazine that contrary to published reports, the baby was not delivered by Caesarean section, but no other details about the birth were given.

Mr Beatie told The Oprah Winfrey Show in April he began his sexual transformation about 10 years ago when he began taking testosterone treatment and had surgery to remove mammary glands and flatten his chest.

Upon deciding to have a child about two years ago, he halted his bimonthly hormone injections and resumed menstruating.

Mr Beatie's wife, Nancy, 46, whom he married five years ago, was unable to conceive because of a prior hysterectomy. Otherwise, he has said, 'I wouldn't be doing this'. His spouse has two grown daughters by a previous marriage.

She said on Oprah's show their parental roles would be fairly traditional despite his transgender status. 'He's going to be the father, and I'm going to be the mother,' she said.

The couple, who operate a T-shirt printing business in Bend, Oregon, are legally married and he is recognised under Oregon state law as a man.