Mr Justice Peter Jackson is the latest judge to raise concerns, issuing a warning after analysing a family court dispute over a baby girl whose lesbian parents separated.
He said the case was “one more example” of problems which could arise.
Earlier this year, another judge, Mrs Justice Eleanor King, issued a similar warning after analysing another case.
Mr Justice Peter Jackson said the case he analysed involved two women — one English and one Irish — who had been in a relationship for about 18 months.
They had decided to have a baby together and found a sperm donor on the internet.
The Irish woman gave birth and the couple lived together in England and shared the baby’s care.
Mr Justice Peter Jackson said the couple separated earlier this year and the Irish woman took the baby to Ireland. The judge said the English woman was fighting for contact with the child.
“These proceedings concern a baby girl now six months old,” said Mr Justice Peter Jackson.
“They are one more example of the painful legal confusion that can arise when children are born as a result of unregulated artificial conception.”
The judge voiced concerns in a written ruling following a hearing in the Family Division of the High Court in London.
He concluded that the baby’s “removal” to Ireland by the Irish woman was lawful and an English court did not have jurisdiction to deal with issues relating to parental responsibility.
But he also concluded that at the time the girl was taken to Ireland, “family life” — as defined in the European Convention on Human Rights — had existed between the baby and the English woman.
No one involved in the case was identified.