The reality television star’s rapper boyfriend Kanye West announces the news to fans at a concert.9:51am UK, Monday 31 December 2012

Reality television star Kim Kardashian and rapper Kanye West are expecting their first child, it has been revealed.

The performer announced that his girlfriend is pregnant to fans at his concert on Sunday night.

He told the crowd of more than 5,000 at the Ovation Hall at the Revel Resort in Atlantic City by singing: “Now you having my baby.”

West also told concert goers to congratulate his “baby moma” and that this was the “most amazing thing”.

Kardashian’s family have also been talking on Twitter about the news.

Her sister Kourtney Kardashian tweeted: “Been wanting to shout from the rooftops with joy and now I can! Another angel to welcome to our family. Overwhelmed with excitement!”

While her other sister Khloe wrote: “I’m excited for Kanye and my sister! There’s nothing like bringing life into this world! Let’s keep Gods blessings coming!”

Messages of congratulations also came from Kardashian’s younger sisters Kendall and Kyle Jenner, who tweeted: “Whos excited about the KIMYE babbyyy?!”, and “Congrats to this beautiful couple. I love you guys.”

Her mother Kris Jenner also tweeted, writing: “Oh BABY BABY BABY!!”

Kim and her family star in the television reality show Keeping Up With The Kardashians, as well as a number of spin off series.

Representatives for the couple have not yet issued a statement about the pregnancy.

The rapper and reality TV star went public with their relationship in March.

Kardashian married NBA player Kris Humphries in August 2011 but separated just two months after their lavish wedding, which was aired on US television channel E! as a two-part special with magazines paying for exclusive pictures.