Two heartbeats were discovered by a technician during a couple's 12-week scan for their second child.
"Sarah and I looked at each other in what can best be described as the delighted panic that is the 'oh dear God it's twins' moment," Giles Hardie told AAP.
But within a moment, their delight turned to confusion and then devastation.
The technician asked the Hardies to move into another room as she discussed the scan with a senior colleague.
"He sat down and explained that yes, it was twins, but they were conjoined twins, and in fact there was no chance of survival," Mr Hardie, a radio producer from NSW's mid-north coast, said.
"That was obviously fairly devastating."
Once home, the couple called their parents and closest friends, and then went to see their specialist.
"They used the delightful terminology that Sarah would need to have a scrape," he said.
"There was no capacity for these twins to survive because of the nature of the way in which they were conjoined."
He described watching his pregnant wife getting wheeled away for the day surgery as "the single most terrified I've ever been".
After, he was focused on Sarah's physical and emotional healing.
Mr Hardie said he became the unofficial spokesperson for his relationship as he fielded calls from friends and relatives, where he both broke the news that they were pregnant with twins and had lost the babies.
"One of the lessons you learn is how to tell someone without taking them on a rollercoaster," he said.
"The first couple of times, you tell someone who didn't know you were pregnant, they get extremely excited for you in the first breath, only for you to then give them a gut punch."
Secrecy in the first 12 weeks of pregnancy can leave people grieving in isolation, he said.
The Hardies lost their babies 13 years ago and while pregnancy loss support has since improved, it is still lacking for many birthing partners.
Mr Hardie wished he had been offered support, even just a pamphlet, from the moment they were told there was a problem with the pregnancy at the 12-week scan.
"A pamphlet that basically said: 'So you're going to lose your baby. These are the things you're going to have to go through. This is what your partner is going to have to go through. This is how you can help her. This is how you can help you'," he said.
Seeing the need, pregnancy loss charity Pink Elephants recently released a Dad's Circle with support online for partners.
"We need to make sure that dads have a safe space for their own grief, where they're not just in the position of support," chief executive Sam Payne said.
"And that doesn't take away from the woman, if anything it adds to the support for her."
Pink Elephants Pregnancy Loss Helpline 1300 726 306