Chris Pratt has gushed about his son to show his support on World Prematurity Day.

The 37-year-old actor took to social media on Thursday (17.11.16) to share a heartfelt message about his four-year-old child Jack - who he has with his wife Anna Faris - and Chris has revealed despite weighing ''just over three pounds'' when he was born he is ''perfectly healthy'', and he has credited March of Dimes organisation for their help.

The 'Jurassic World' star shared a clip of Jack playing in the garden with a Praying Mantis on his Instagram account, which he captioned: ''As many of you may know, our son Jack was just over 3 pounds when he was born. Thanks to scientific advances made possible by #marchofdimes funding, today he's a perfectly healthy, curious 4 year old. Today is #worldprematurityday. 15 million babies are born #prematurely each year around the world. And 1 million of them won't live to celebrate their 1st #birthday. The @marchofdimes strives for a world where every #baby has a fair chance, yet this is not the reality for many mothers and babies. Join me in supporting their efforts to give every baby a fighting chance by clicking the link in my bio. Thank you! God Bless!!! (sic).''

And the star also took to Twitter to help raise awareness about the condition.

He tweeted: ''Today is #WorldPrematurityDay. Did you know that 15 million babies are born prematurely in the world each year... (sic).''

However, this is not the first time the Hollywood hunk has shown his support for the foundation, which helps to support mothers and children, as in two years ago Chris gave a touching speech about fatherhood.

Speaking previously, the dark-haired heartthrob said: ''I've done all kinds of cool things as an actor: I've jumped out of helicopters and done some daring stunts and played baseball in a professional stadium, but none of it means anything compared to being somebody's daddy. I made promises in that moment about what kind of dad I wanted to be and I just prayed that he'd live long enough that I could keep them.

''Our Jack went from a small, helpless little squirt to a strong, smart, happy, funny, beautiful boy who loves monster trucks and 'Daniel Tiger', and, believe it or not, loves vegetables.''