The Baldwin family just got a little bigger.
"We had a baby last night," she wrote alongside a photo of the 36-year-old fitness guru and the 62-year-old actor admiring their little one. "He is perfect, and we couldn't be happier."
As for those wondering about the bundle of joy's moniker, Hilaria said they'll have to "stay tuned for a name." Of course, several of their famous friends and family members congratulated them on the big news.
"Congratulations to the entire battalion!!" Billy Baldwin wrote in the comments section. "I think Guillermo Eduardo has a fabulous ring to it!!"
Added Katie Couric, "Mazel!!!! He's beautiful."
The birth came five months after Hilaria announced the pregnancy.
"I'll let the baby do the talking because I don't have the words to express how this sound makes us feel," she captioned a clip of the baby's heartbeat in April. "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 then continued to keep fans updated, such as by posting photos of her baby bump and revealing why she wanted to keep the sex of the child a surprise.
"I always kind of spill the beans. I'm such a sharer," she said on E!'s Daily Pop earlier this month. "And this time, we're going to have it be a little bit of a different experience. You do this this many times, why don't we make it different?"
"We are very sad to share that today we learned that our baby passed away at 4 months," the star wrote on Instagram in November. "We also want you to know that even though we are not ok right now, we will be. We are so lucky with our 4 healthy babies—and we will never lose sight of this."
Hilaria and Alec, who wed in 2012, are also parents to Carmen, 7; Rafael, 5; Leonardo, 3 and Romeo, 2. In addition, Alec shares 24-year-old daughter Ireland with his ex-wife Kim Basinger.
Congratulations to the happy family!