Queensland court formalises parentage in rare surrogacy case of biologically unrelated twins
A Queensland woman gave birth to twins with different biological parents in November 2025, forcing two families to seek court orders to untangle a surrogacy
A Queensland woman gave birth to twins with different biological parents in November 2025, forcing two families to seek court orders to untangle a surrogacy case a judge described as “sufficiently atypical.” The children, born on the Gold Coast, have already been raised separately by their respective biological parents.
The case, decided in the Children’s Court of Queensland, is believed to be an Australian first and arose from an “altruistic” surrogacy arrangement that collided with an unplanned natural pregnancy. The result was unusual even by the standards of assisted reproduction. Very unusual.
How the pregnancy unfolded
According to court documents, the woman, identified as DZ, agreed in September 2024 to act as a surrogate for a couple known as BNJ and DRJ. The agreement said any child born through the arrangement would be treated as the child of BNJ and DRJ, not of DZ and her spouse, FZ.
BNJ was then 25 and worked as a childcare educator. DRJ, then 28, was a cabinetmaker. DZ and FZ were both 27 at the time and already had five other children, including one born in 2024.
A single embryo was transferred on April 11, 2025. Four days later, DZ had a positive pregnancy test. Two weeks after that, an ultrasound showed something no one had expected: she was carrying two babies.
Testing later confirmed that the boy was the child of BNJ and DRJ, while the girl was DZ and FZ’s biological daughter. The twins developed together in the womb and were delivered by caesarean section in November 2025.
Why the court had to step in
Under Queensland’s Surrogacy Act, the arrangement created a legal problem the law did not seem to anticipate. The state’s rules were written to deal with “birth siblings” in surrogate pregnancies, but not with twins who shared a birth date and gestation yet had different biological parents.
Judge Jodie Wooldridge ultimately found the babies were not “birth siblings” for the purpose of the law. The ruling formally recognised the parentage of the biological parents and separated the two children in legal terms, even though they were gestational twins.
There has been no dispute between the families. Each has been raising its own biological child separately since the birth, and the case reached court only to clear up the paperwork and the law. Still, the facts pushed the system into new territory.
A rare case with wider implications
Similar edge cases have surfaced elsewhere in reproductive medicine, but this one stands out because it combines surrogacy, embryo transfer and a concurrent natural pregnancy in the same womb. The result was two babies born on the same day, under one pregnancy, to two sets of parents.
That is the kind of scenario lawmakers do not often plan for. Courts usually get involved when parentage is disputed. Here, no one fought over the children. The legal question was narrower, but still crucial: how to classify twins who were siblings in gestation only.
The judgment leaves Queensland with a precedent for a situation so rare it had not been contemplated by the state’s surrogacy laws. And it puts a spotlight on how fertility treatment and family law can collide in ways that are hard to draft for, until they happen.
