Kanye West announced that Kardashian is pregnant during a New Jersey concert on Sunday (December 30), with a spokesperson for the pair later confirming the news.
The Keeping Up with the Kardashians star has since taken to her official blog to share her joy about becoming a first-time mother next year.
"It's true!! Kanye and I are expecting a baby," she declared.
Kardashian went on to write: "We feel so blessed and lucky and wish that in addition to both of our families, his mum and my dad could be here to celebrate this special time with us.
"Looking forward to great new beginnings in 2013 and to starting a family. Happy New Year!!!"
The couple have been congratulated on the pregnancy by Kim's mother Kris Jenner and her sisters Kylie Jenner, Kendall Jenner, Kourtney Kardashian and Khloe Kardashian.
Ryan Seacrest - who produces Keeping Up with the Kardashians - also extended well-wishes to the happy couple.
"It's true :) @KimKardashian & @KanyeWest are having a baby! congrats u guys," he tweeted.
Kim and West were first linked in early 2012, mere months after the reality star ended her marriage to basketball pro Kris Humphries.
Watch Kanye West announce the news at his Atlantic City show below: