The reality TV star`s boyfriend Kanye West shared the couple`s happy news during a performance at Revedl in Atlantic City, New Jersey on December 30, and the brunette beauty`s representative has now confirmed the news.
During the show, Kanye - who has been dating Kim since April 2011 - told the audience to "stop the music and make noise for my baby mama."
While Kim - who is believed to be around 12 weeks pregnant - hasn`t spoken about her pregnancy, her family are delighted by the news.
Sister Kourtney Kardashian - who has two children, three-year-old Mason and five-month-old Penelope, with partner Scott Disick - tweeted: "Been wanting to shout from the rooftops with joy and now I can! Another angel to welcome to our family. Overwhelmed with excitement! (sic)"
Sibling Khloe Kardashian added: "Keeping secrets is hard with so many family members! Especially when you are so freaking excited!!!!! LOVE is everything!!!! (sic)".
And Kim`s mother and manager Kris Jenner is delighted.
She tweeted: "Im a happy girl !!!!!!!!! Wowza! (sic)"
Kim, 32, and 35-year-old Kanye spent the festive period together and were seen with the `Keeping Up with the Kardashians` star`s family watching her brother-in-law Lamar Odom playing basketball for the Los Angeles Clippers on Christmas Day (25.12.12).
However, they left at half time with Kim later tweeting she felt "unwell".
She added: "In bed with the flu all day. Praying this goes away fast!"