The proud parents will now have double the reason to celebrate on Christmas each year after welcoming their twin daughters into the world on Thursday.

The girls, who are yet to be named, were born just eight minutes apart at 7.44am and 7.52am at Centenary Hospital for Women and Children.

Mum was doing well and said she could not have asked for a better way to celebrate Christmas Day.

"I'm feeling really good," the 24-year-old said.

Mr Muench, 30, said they were yet to decide on names for the twins.

"They can just be the Christmas twins for a little while," he said.

Ms Harrison said her partner knew the twins were going to be Christmas babies.

Ms Harrison was 37 weeks and three days pregnant when the twins decided they couldn't wait any longer to enter the world.

"We came in on Wednesday morning for a discussion about what was going to happen and then we went home," she said.

But after enjoying a Christmas Eve dinner, the couple had to make a return to hospital with the twins on their way.

The proud parents were not the only ones overjoyed with the twins' arrival, with big brother Travis, 4, also pretty pleased that Father Christmas decided to bring him two baby sisters.

"I think he's over the moon and he's adjusting really well," Ms Harrison said.