The 33-year-old pregnant singer revealed the baby's gender while performing at a concert in Malaysia, reported Ace Showbiz.
"It's fun, I'm having another little one. This is her first show. You guys are her first show," she told the audience."
The baby will be Aguilera's first child with fiance Matt Rutler. She has a six-year-old son Max Liron from previous marriage to Jordan Bratman. Aguilera announced her engagement to Rutler on Valentine's Day and confirmed her pregnancy in the same month.