The boy band member announced via his twitter page on Tuesday (03.07.12) that his spouse of eight months, Rochelle Karidis, will be having a daughter.
He wrote: ''Baby announcement coming soon!''
He later revealed to his hundreds of thousands of followers: ''Yay we're having a baby girl!!!!! Little baby Ava Jaymes.''
The 34-year-old singer also posted a video message to his fans on SocialCam.
He said: ''Thank you guys for all of your love and support. This will be the first Backstreet girl.''
He originally announced they were expecting a child back in April, more than two years after proposing to Rochelle in January 2010.
The special occasion took place during a live concert in Las Vegas, Nevada and they got married in December 2011 at the Beverly Hills Hotel in California.