Beyonce to talk about miscarriage in documentary

London: R&B star Beyonce will reportedly open up about her rumoured miscarriage in her upcoming documentary.

The `Halo` singer is said to reveal how her loss inspired her to write the saddest song of her life, reported Digital Spy.

Beyonce`s husband Jay-Z sparked rumours that the singer had previously suffered a miscarriage before the birth of daughter Blue Ivy when he penned a track about her last year.

In the song he rapped, "Last time the miscarriage was so tragic/We was afraid you`d disappear/But nah baby you magic."

Beyonce also opens up about her successful music and acting career in the self-directed documentary, which airs on February 16 on the cable network.

She will also take to the stage next weekend for her much-anticipated Super Bowl halftime performance and has posted rehearsal pictures teasing her set.