Mariah explained: “You can tell the personalities a bit. In viewing our ultrasounds, our boy is all ready like Nick, like, ‘Here I am, take my picture or don’t, and our girl is coyly facing the other way, like, ‘No pictures,’ waiting for a proper debut.
“I took some ultrasound footage of them in the womb that I think they’ll definitely find interesting later in life.”
Mariah also spoke of her belief that Nick, 30, will be a wonderful father, revealing he is already devoted to their twins.
She added in an interview with Britain’s OK! magazine: “Nick is so excited about being a father. He already has this natural talent with children, they take to him right away. He’s so nurturing, loving and fun.
“He definitely will be a hands-on dad. He already reads stories to my tummy.”
However, Mariah is concerned about Nick’s work load and hopes they can both spend the coming months quietly at home.
She added: “Hopefully Nick will take a bit of time off. As I like to say, he’s the hardest-working man in showbusiness, so that’s great, but I’m like, ‘Alright already, take a break, stay put.’
“This is one of the few times in my career I’ve actually taken it easy, sort of. I am looking forward to spending quality time with the babies and Nick and that’s our plan.”