Jack Osbourne & Fiancee Welcome Baby Pearl

Access Hollywood
Jack Osbourne and Lisa Stelly seen in the hospital in Los Angeles after his appendix removed on March 26, 2012 -- Twitter

Jack Osbourne has gone from reality star son to father.

The former star of MTV's "The Osbournes" and his fiancee, Lisa Stelly, have welcomed a daughter.

PLAY IT NOW: Kelly Osbourne Talks Staying Skinny & Her ‘Hot’ NewNowNext Awards Makeout!

An editor (Rosie Nixon) for the UK's Hello magazine first revealed the news on Twitter

"HELLO! can exclusively announce the safe arrival of @MrJackO & @lisamarstelly 's baby girl Pearl weighing 8lb 6oz. Love & congrats to them!" the editor wrote.

VIEW THE PHOTOS: The ‘Fierce’ Miss Kelly Osbourne

Jack Retweeted the message, apparently a confirmation of the happy news.

In recent years, Jack went from reality star to filmmaker, producing the documentary "Wreckage of My Past: The Story of Ozzy Osbourne," about his father, the legendary heavy metal rocker.

Copyright 2012 by NBC Universal, Inc. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

VIEW THE PHOTOS: Hollywood Dads & Their Adorable Little Ones!