The pair, who married in 2008, announced Carey's pregnancy in October 2010, although it wasn't until December that news that the pair were expecting twins was made public.
Now Carey tells Life & Style, "There were fan contests on Twitter about what gender they are and rumors about them being two boys or two girls -- but nobody guessed this!"
Carey expressed excitement about expecting children of both sexes, but the Hello Kitty fan says she won't be imposing any of her girly-girl aesthetic on her kids. "Even before we announced it was twins, I was trying to keep everything gender-neutral because I didn't want to impose an identity on them too soon," she says.
During an appearance on 'The Ellen DeGeneres Show,' Carey said of her design choices, "I'm not going to impose pink on a girl. You think I'm really going to go that hard with it?" to which Ellen responded, "When that baby comes out, you're going to have high heels on it immediately."
The singer, who initially kept mum about her pregnancy despite her growing belly, first broke the news of her "double treat" to another power couple: Barack and Michelle Obama.
Following her performance at TNT's 'Christmas in Washington' special, the singer ran into the Obamas backstage and told them the news. Cannon said of the event, "Because of the excitement, because of the emotion, she was overwhelmed [and] she shared with the President and First Lady that we are having twins."