Rapper Jay-Z, who became the proud parent of a baby daughter Saturday, has revealed in a song that his R&B star wife Beyonce has had a miscarriage earlier.

Jay-Z and Beyonce Knowles. PICs/AFP

The 'Empire State of Mind' hitmaker made the revelation in a new song 'Glory' which he posted on his social website Life and Times.

The tune is a tribute to the couple's new baby, Blue Ivy Carter, who was born in New York late Saturday night.

In the song, Jay-Z, 42, talks about where the child was conceived (in Paris) and even reveals that Beyonce, 30, had a lost a child one point, reported Daily Mail.

"Last time the miscarriage was so tragic/We was afraid you'd disappear/But nah baby you magic." The sound of crying Blue Ivy can be heard at the end of the song.

The track was produced by Pharrell and credits the new arrival as 'B.I.C.' Other lyrics include: 'The most amazing feeling I feel, words can't describe what I'm feeling for real / Baby, I paint the sky blue, my greatest creation was you.

"You're the child of destiny / you're the child of my destiny / you're my child with the child from Destiny's Child." Destiny's Child is the girl band Beyonce started her singing career with. Blue Ivy Carter is the first child for the power couple, who wed in 2008 in a private ceremony after a years-long courtship.