The actress is also mom to Atticus and Autumn.
On Thursday, Hewitt announced the news via Instagram by sharing a photo of her baby bump with writing on it. "Well, this is how my kids sent me to the hospital. My belly was a big hit," she captioned the photo before sharing the quote, "It is said that women leave their bodies in labor… they travel to the stars to collect the souls of their babies, and return to this world together."
The proud mom further confirmed the birth of her son, adding, "It was my greatest honor to go and collect you Aidan James. Now back to snuggles and resting. 👶🏻🧡."
Hewitt first shared the exciting news of her third pregnancy in an Instagram post on May 18. "Oh baby!" she captioned a photo of herself with a positive pregnancy test. "We have another one on the way. So excited to finally share this news with all of you. Thank you @clearblue for being part of our journey and giving us a platform to share this news!"
The 9-1-1 star, who also shares 7-year-old daughter, Autumn, and 6-year-old son, Atticus, with Hallisay, later spoke to People, about her growing family, saying: "We had always been open to a third, but definitely didn't think in the crazy year that the entire world was having that it would necessarily be this moment. I feel like we've been able to so far raise two really special kids who will be great role models. This has been such a pleasant, beautiful, surprising gift in this time to be able to get to do all that again with another little human."
As for how she found out, Hewitt gushed: "One night, my kids and I were laying in bed watching TV and a Clearblue commercial came on television. My son out of nowhere was like, 'Hey Mommy, you should order one of those in case there's a baby in your belly.' I was like, 'How rude! I just ate a big dinner. What is he talking about?' It stuck with me, and they've been asking off and on for a year or so for a sibling. We weren't closed off to the idea, it just wasn't something that we were actively thinking about."