Lily Allen has poured out her heart about the baby she lost in a new song she hopes to include on her comeback album.

The Smile hitmaker miscarried a son six months into a 2010 pregnancy, and now she has opened up about the tragedy in an untitled new tune, which she tells Q magazine is "a really sad, really powerful track".

Allen says, "I hope it makes the final cut, because it's a really important song to me."

Following her miscarriage, the singer had two daughters with husband Sam Cooper. She also miscarried a child in 2008.