"They're going to have to go into special care for a little bit which is just the way it is when they come premature.
"Look we're not 100 per cent ready for them, nothing's set up, we've got everything there to build. But the main thing is Liss is healthy and the two boys are healthy. And soon, we're gonna be a mum and dad."
The engaged pair, who met on the Channel 9 dating show late last year, said they had planned to spend the weekend building the nursery but their twins had other plans.
They are yet to reveal their babies' names.
Three months after the controversial pair decided to stay together on the show's finale in April, they announced they were engaged and expecting twins.
"It's been a whirlwind, but we're so incredibly happy," Rawson told New Idea magazine.
"I couldn't stop crying, it was very emotional. I think I said 'holy sh*t' seven times."
Ruthven, who copped criticism during his time on the show for what viewers saw as manipulative behaviour, told the publication the couple were now just looking to the future.
"We're not doing this for anybody else, it's about us – we're cementing our love," he said.
"Melissa deserves to be happy and I'm apparently very good at that, so I'm looking forward to making it all official."
