The Break On Me singer spotted the woman's odd sign from the stage as he performed at the Bridgestone Arena, and pulled her and a friend up to quiz her about the strange plea.

"I have no idea what song that would be!" an amused Urban told the expectant mum, who revealed she was having a boy and proposed he sing Blue Ain't Your Color, suggesting he change the lyrics a little to reflect her baby's gender.

Urban happily obliged, but his efforts failed to sway the unborn child to make his appearance during the show, which also included guest appearances by Maren Morris, his tour opener Brett Eldredge, and Eric Church, who surprised the audience by joining Keith for renditions Record Year and their duet We Were Us.