Lyndal wanted answers about her family. A DNA test turned her world upside down.

A few months after getting married, Lyndal Bubke decided to take an ancestry DNA test and trace her family history.

Speaking to The Guardian, she said she'd recently watched the documentary Our Father, about former fertility doctor Don Cline, who spent 30 years secretly using his own sperm to impregnate women. He had 94 confirmed children.

Her parents got in just ahead of the results landing to tell her the news: Lyndal had been conceived using a sperm donor.

The more she thought about it, the more it made sense. While Lyndal's parents were blonde, she was brunette.

Finding out was a shock. Learning she had 11 confirmed half-siblings was a bigger one.

Today, she knows the number is 77 and could be even higher.

Watch: Lyndal Bubke on discovering she has 77 half-siblings. Post continues below.

Appearing on A Current Affair on Wednesday with one of her half-siblings, Gabe, Lyndal said her parents were told the donor was a blonde medical student.

Meanwhile, Gabe's family was told he was a sports scientist.

"Our very brunette donor works for the government. He hasn't got a university degree," Lyndal said.

"Our donor donated 325 times and they kept using that sperm for years and years and years."

While not every donation leads to a pregnancy, Lyndal estimates she could have between 250 and 350 siblings, given that sperm was used at clinics by multiple doctors and could have been sold interstate between clinics.

"That's a reasonably conservative estimate," she said.

Some of the siblings are in touch. They have regular Zoom calls and have a group chat named Cheaper By The Dozen.

"There are way too many of us for it to be rare," Lyndal said.

"You go to these clinics, you trust the doctors… and this happened. Without the legislation, it will happen again."

When she found out she was donor-conceived and was waiting on her DNA test results, she told The Project her first thought was: "Thank God my husband's done a test and we know we're not related."

"It's really upsetting stuff," she said.

Lyndal and Gabe. Image: A Current Affair.

Lyndal is amongst the voices calling for a national framework for the donor industry, which is worth $800 million each year.

One in 18 children is born from IVF treatment in Australia, according to the Australian and New Zealand Assisted Reproduction Database.

While there are state and territory-based IVF guidelines for regulating the industry, there are no national laws or an independent governing agency policing fertility clinics in Australia.

Currently, there are no national rules regarding the limits on the number of families a donor can contribute to, or how and where records about donors and donations are kept.

Donor limit rules vary from state to state and even clinic by clinic in some jurisdictions.

Victoria, NSW, WA, SA and ACT have their own regulations setting donor family limits, typically around five to 10 families. In states and territories without specific laws, clinics may set their own caps, usually guided by national ethical standards, but these are not centrally enforced.

Records are kept state by state and clinics in jurisdictions without central registers manage their own records.

Before 2005, donors could remain anonymous in most states. Now, across all states, donor anonymity is prohibited, and identifying information is available to donor-conceived children once they turn 18.

For many donor-conceived people, especially those born before donor identification laws, access to detailed health information or direct contact with their donor often depends on whether the donor consents to share updated records or identify themselves.

In Lyndal's case, her fertility records were possibly lost, destroyed or never created in the first place. The Guardian reports her family's fertility doctor has since died, and her clinic Queensland Fertility Group (QFG) says they can't disclose her donor's identity without their consent, meaning she'll likely never get answers.

The clinic told ACA it has since introduced more rigorous protocols. It said it strongly advocates for national reform of IVF regulations, including a compulsory national donor conception registry, a consistent national family limit, and an independent oversight body for the IVF sector.

The peak body for reproductive medicine, Fertility Society of Australia and New Zealand, has called for a national regulatory framework. A review by the society suggested a single national register and genetic bank for donors and donor-conceived individuals.

In June, federal and state health ministers announced an immediate review of the IVF sector, following growing concern after recent high-profile bungles in the sector.

It will consider whether a national regulator is needed to replace state-based regulators.

This week, Federal Health Minister Mark Butler said he was open to a national regulatory system.

"I think self-regulation isn't working, and I don't think it's inspiring the confidence that parents need," he told ABC.

Feature image: A Current Affair.