An IVF mix-up that saw a Brisbane woman give birth to someone else's baby after the wrong embryo was transferred could prompt a legal battle over the child's parentage, a surrogacy law expert says.
Monash IVF discovered the mistake in February, after the birth parents asked to transfer their remaining frozen embryos to another provider.
The fertility company, which operates across Australia, says human error led to a different patient's embryo being implanted. The baby was born last year.
The woman was receiving treatment at a clinic in Brisbane.
Family creation lawyer Sarah Jefford, who specialises in surrogacy and donor conception law, said the mix-up could set a legal precedent.
"There are presumptions in Australia about the birth parents being the legal parents of the child," she said.
"But whether the genetic parents want to come forward and start a discussion about that, then we'll have to wait and see."
'Human beings make mistakes'
Professor Gab Kovacs, an IVF pioneer and former director of Monash IVF, said it was a "terrible, sad situation all round" that was unlikely to have been tested before in Australia.
"While this is life altering for the couples involved, the next person who will be most shattered is the scientist responsible for this mistake," he told ABC Radio Melbourne.
"I've got no idea what the legal situation in Australia would decide, I don't think it's been tested before.
"I don't think there's much more that can be done, we just have to accept that human beings make mistakes."
Professor Kovacs said Monash IVF's processes were robust.
"Everything is double-checked for the last 40 years. Every time we handle tissues, someone's got to sign off on us," he said.
"If you do many, many procedures — over 100,000 a year in Australia — and each IVF site has got several steps where the sperm and the eggs are handled, there is a possibility of human error."
Associate professor Alex Polyakov, a fertility specialist from the University of Melbourne, said it was an "extremely rare" scenario.
"I think it's important to stress that this is a nightmare scenario for a fertility centre, and there are very robust protocols when we handle either sperm, eggs or embryos, and they are in place in all labs in Australia," he said.
"I think there must be a number of factors or a number of events that took place that unfortunately resulted in this situation.
"It is almost impossible for this to happen, but just like flying in a plane, it is safe, and occasionally, a plane could crash due to human error, or a number of human errors."
Dr Alex Polyakov said other patients had "no cause for concern".
"It's not a systemic issue … it's an isolated incident, a very unfortunate one, clearly," he said.
'Almost unbelievable'
Fertility educator Lucy Lines said it was a devastating mistake that would "send ripples through the whole IVF community".
"I actually had a cold sweat. As an ex-embryologist it's your absolute worst nightmare," she said.
"It is so, so, so rare, and there are so many checks and balances in place that make it almost unbelievable that it could've happened."
A Victorian government spokeswoman said it was a matter for the Queensland Health Department.
"The Health Regulator will work with Monash IVF — and all clinics in Victoria — to reinforce safeguards and ensure any risks are identified and mitigated in light of this alarming incident in Queensland," she said in a statement.
On Thursday, Monash IVF CEO Michael Knaap said the families involved were being supported.
"All of us at Monash IVF are devastated," he said.
Mr Knaap said he was confident it was an isolated incident but that the company had commissioned an independent investigation to determine how it happened.
Queensland Health said the mix-up was reported to the department, which is the new Assisted Reproductive Technology Regulator, and it was working with Monash IVF to reinforce safeguards in their Queensland clinics.
Last year, Monash IVF settled a class action with no admission of liability, following claims it used inaccurate genetic testing and destroyed potentially viable embryos.
More than 700 patients across the country were involved in the class action which saw Monash IVF agree to pay a $56 million settlement.
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