A young child may become the first person in England and Wales without a “mother” listed on their birth certificate, if a woman now living as a man wins a legal case.
The unnamed transsexual gave birth to the child, but according to the law is now a man.
Lawyers claim human rights are being breached by requiring women who give birth to register as “mother” rather than “father”.
The High Court says the case is the first of its kind and heard preliminary arguments on Thursday.
Mr Justice Francis said ministers may have to act if the court rules the current system is flawed.
Barrister Hannah Markham QC explained that her transsexual client believes the current law interferes with the right to a private and family life.
But Sarah Hannett, speaking for the Registrar General, said the law forbade her client from registering people who give birth as anything other than “mother”.
The judge said media outlets could not report the young child’s sex or age, or give any geographical information.
A decision is expected following a trial in the autumn.