"Mr Justice Francis heard how the man was born a woman but "realised he was trans" several years ago.
Lawyers said he had lived "as a man" since then and had undergone surgery to "re-contour" his upper body.
The High Court judge was told that the man was granted a gender recognition certificate more than a year ago, before the baby was born."
http://Mr Justice Francis heard how ...baby was born.
A baby could become the first person without a legal mother if a transgender man wins a historic court battle.
Lawyers representing the parent told a judge that he had been biologically able to get pregnant and give birth but had legally become a man when the child was born.
The man wants to be identified as the child's "father" or "parent" on a birth certificate, however a birth registrar told the man the law requires people who give birth to children to be registered as mothers.
The man has since taken legal action against the body set up to administer statutory provisions relating to the registration of births and deaths after complaining of discrimination.
He said forcing him to register as the child's "mother" breached his human right to respect for private and family life.
The man added that such "interference" was not proportionate or necessary in the light of changes which had "evolved in society".
It is an accepted fact that a female who transitions to male may in law maintain the ability to conceive and give birth to a child
Hannah Markham QC
Mr Justice Francis yesterday heard preliminary arguments from lawyers representing the man and lawyers representing The Registrar General for England and Wales at a High Court hearing in London.
The judge said the issue had never been raised in a court in England and Wales before. He added that if the man won his fight ministers might have to consider changing the law.