Alec and Hilaria Baldwin have welcomed their fourth child.

The 60-year-old actor and his 34-year-old wife have revealed they are now the proud parents of a fourth child after Hilaria gave birth to their new baby boy.

In an Instagram post which showed the new parents gazing down at their tiny tot, Hilaria wrote: ''He's here! He's perfect! 8lbs 2oz #wegotthis2018 (sic)''

Alec posted the same picture on his own Instagram account, and captioned it: ''Here we go again! #BaldwinitosEverywhere (sic)''

The couple, who married in 2012, are already the proud parents of daughter Carmen, four, son Rafael, two, and 20-month-old son Leonardo, whilst Alec has 22-year-old daughter Ireland from a previous relationship.

The arrival of the couple's fourth child will no doubt be good news to young daughter Carmen, as Hilaria previously revealed the toddler is already keen for her parents to have yet another baby, as she wants a little sister.

Hilaria said: ''Mommy doesn't even want to think about another one right now. But we'll see if she [Carmen] bullies me into it.''

The pair don't have a name for their new arrival just yet, as they claimed they're going to wait and see what monikers suit him in the coming days.

Hilaria said previously: ''This is the first one that we really don't know going into it, and we're going to see what he looks like and take a good look.''

Earlier this year, the couple were making sure they packed in plenty of time together as a couple before their hands were full with another young child.

Hilaria wrote on Instagram: ''Alone time before number 4 comes...Alec always tells me that no matter how many kids we have and that we are ''husband'' and ''wife'', I'll always be his girlfriend. We really work hard to maintain this. How do you feel about this in your own relationships? #WeGotThis2018 is @apeainthepodmaternity (sic)''