Baldwin, 36, welcomed her fifth child, a son, with her husband, actor Alec Baldwin, 62, on Tuesday.
Baldwin shared the news Wednesday on Instagram alongside a photo of herself with Alec Baldwin and their baby boy.
“We had a baby last night. He is perfect and we couldn’t be happier. Stay tuned for a name,” she captioned the post.
Alec Baldwin’s brother Billy Baldwin, actor Mario Lopez, journalist Katie Couric and actress Jaimie Alexander were among those to congratulate the couple in the comments.
“Congratulations to the entire battalion!!I think Guillermo Eduardo has a fabulous ring to it!!” Billy Baldwin wrote.
“Mazel!!!! He’s beautiful,” Couric said.
Baldwin and Alec Baldwin married in June 2012 and already have a daughter, Carmen, 7, and three sons, Rafael, 5, Leonardo, 3, and Romeo, 2. Alec Baldwin also has a daughter, Ireland, 24, with his ex-wife, Kim Basinger.
Baldwin announced her pregnancy in April alongside a video featuring her unborn child’s heartbeat.
“Just got the great news that all is well and all is healthy with this little munchkin. I wanted to share this with you. Here we go again,” she said on Instagram.
Baldwin previously experienced two miscarriages in 2019.