Socialite Kourtney Kardashian (30) and long-term boyfriend Scott Disick (26) have welcomed a new arrival, a 7lbs 6oz boy.
The baby, who has been named as Mason Dash Disick, was born in Cedars Sinai Hospital in LA on Monday.
His middle moniker is an abbreviation of Kourtney's surname, and the name of the family's clothing boutique.
Proud aunt Kim Kardashian used Twitter to spread the word, tweeting: ‘I'm an auntie! Mason Dash Disick is here. We are so happy.'
Although the pregnancy was unplanned, both parents are said to be delighted with the family addition.
Kourtney and Scott broke up earlier this year, but reconciled after finding out she was pregnant.
At her November baby shower, the excited mum-to-be said, ‘I'm in a new chapter in my life - it's fun'.