A woman who became a man is believed to have become Britain's first "male mother" by giving birth despite his sex change operation.
Medical experts said that if the womb was not removed in sex change surgery, there was nothing to stop a transgender man from having a child.
The Press Associated cited a transgender support group, the Beaumont Society, as saying the British man, thought to be in his 30s, had the child last year.
Worldwide, a handful of other "male mothers" are known to have given birth.
Thomas Beattie, from Oregon, became the world's first "pregnant man" in 2008, according to the Daily Mail, after a hysterectomy left his wife unable to conceive. Beattie, who had retained his own womb, self-inseminated sperm from a donor. He has now reportedly borne three children.
Meanwhile, Scott Moore, who lives in California with his husband reportedly gave birth in March 2010; and Israeli Yuval Topper, who in Decemeber 2011.
The Daily Mail cites experts as saying men who've retained their wombs can produce and using his own eggs, as well as conceive and give birth naturally. Or else they can use donor eggs and sperm, hormone treatments, IVF and a caesarean sections.
Few details are known about the circumstances of the British man, however the Beaumont Society's Joanna Darrell said he had approached the society asking for advice about having a baby, and:
"We sometimes get people coming back to say thanks for our help. He got back in touch and said he had had the baby."
The Daily Mail also quoted opponents of transgender men giving birth, on ethical, religious or social grounds
It quoted a former conservative lawmaker Ann Widdecombe as saying: "It is a horrible muddle. What is the child going to think? The key thing is the child, in case anyone forgets that."
Trevor Stammers, a lecturer in medical ethics and former chairman of the Christian Medical Fellowship, expressed concern that the man's pregnancy and birth procedure might have been funded by Britain's pubic health system, saying it was "not beyond the bounds of possibility" that the NHS (National Health paid for it.