Kim Kardashian and Kanye West
Kim is reportedly three months pregnant with the couples first child.

They have only just announced that they are expecting their first child, but Kanye West is already planning another collaboration with his pregnant girlfriend Kim Kardashian to celebrate.

The 37-year-old rapper apparently wants to record a duet with the reality star so that they can play the track to their child when the baby is born.

A recording studio is said to have already been booked for the end of January, when the couple will start making music together.

A source told the Daily Star: "Kanye's really soppy. He wants Kim to lay down some vocals while she's carrying his child.

"He thinks it'll be cool for his son or daughter to listen to the track when they're older."

The Keeping up with the Kardashians star confirmed the baby news after the 37-year-old Watch the Throne rapper gave the game away during a gig.

Earlier this week, it was been revealed that the proud parents-to-be plan to document her pregnancy and their up and downs following the birth in a new reality TV show.

"Kim and Kanye are an incredibly dynamic couple, and their baby news is just so exciting," E! Entertainment network president Suzanne Kolb said.

"Like so many Kardashian fans, we love it when this close-knit family gets even bigger. We look forward to sharing the joy as they prepare for more diapers, more bottles and without a doubt, more fabulous baby wear."