Katherine Schwarzenegger and Chris Pratt have welcomed their third baby together.

The 34-year-old author - who already has Eloise Christina, two, and Lyla Maria, four, with the movie star - has announced via social media that she's given birth to a baby boy called Ford.

In a joint post on Instagram, Katherine and Chris said: "We are overjoyed to announce the birth of our son, Ford Fitzgerald Schwarzenegger Pratt. Mama and baby are doing well and Ford’s siblings are thrilled by his arrival. We feel so blessed and grateful.

"Love, Katherine and Chris (sic)"

The social media post also confirmed that Katherine gave birth to her son on November 8.

Meanwhile, Chris previously opened up about his parenting style, revealing that he wants his children to "feel comfortable expressing themselves".

The Hollywood star - who also has Jack, 12, from his relationship with Anna Faris - told E! News: "I think there's a new age of parenting.

"I grew up, I did exactly what my parents said all the time. I never knew I could say 'no' to my parents. And now I'm a guy who's not super ... didn't have a super healthy grip on his own emotions. So we're trying to raise them in a way that they feel comfortable expressing themselves.

"They still know the meaning of the word 'no' from their mom. When it comes from me, they don't seem to know what that means. And I don't really know what to do about it, but we'll get there."

Chris subsequently heaped praise on his kids, describing them all as "wonderful".

He said: "They are cute and they're wonderful. They're sweet, polite, kind, joyous little angels, and I love them."