The socialite - who recently reunited with her boyfriend, American football star Reggie Bush - has revealed helping her sister Kourtney prepare for the arrival of her first child has made her broody.
She told America's OK! magazine: "This is just the most exciting new step in our lives, and I think everyone in the family can't wait for the baby to come!
"You see what my sister's going through and it's so much fun, and she's picking out cribs and high chairs, and I'm getting her little clothes and little shoes and it's all so cute!"
As well as looking forward to welcoming the new baby, Kim is also thrilled with her sister Khloe's recent wedding to Los Angeles Lakers basketball star Lamar Odom, who she married following a whirlwind romance.
The 28-year-old star said: "My whole family's changed over the course of a few months and, you know, it's just fun. We have all of these new, fun people in our lives and it is like a growing family!"
Kourtney and boyfriend Scott Disick recently revealed they are expecting a boy and according to her sister, the star only made the decision to find out the unborn tot's gender after being pressured by friends and family who wanted to buy gifts.
Kim explained: "She actually didn't even want to find out, so we waited and then planning the baby shower, we're like, 'OK, you got to give us some kind of colour here because we don't know what to do!' And so she found out."
Meanwhile, Kim's step-brother Brody Jenner is delighted she has reunited with Reggie.
He said: "I love it. I was just with Reggie the other night.
"I personally think Reggie is one of the nicest human beings I've ever met in my life. I think he would be an incredible partner for Kim."
Kim and Reggie, 24, dated for two years before ending their relationship in July because they were not spending enough time together.