MTV.com said Carey reveals the babies' genders in an interview for the forthcoming issue of Life & Style magazine, which reports the recording star is due to give birth in April.
"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," Carey told the magazine.
"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!"
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