The pregnant mom took to Instagram to commemorate the special occasion with a throwback photo of Alec down on one knee. In the photo, Hilaria stands in front of him, holding his chin with one hand as daughter Carmen is perched on her hip.
"10 years packed full of so many babies, laughs, tears, frustration, breakthroughs, passion, fear, joy…and everything all in between that our life brings," Hilaria wrote. "Happy anniversary Alec💕."
The actor and the yoga instructor wed in 2012 and welcomed daughter Carmen Gabriela, their first child, in 2013.
PEOPLE confirmed Hilaria's current pregnancy in March, with Hilaria recently revealing that they are expecting another baby girl.
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The couple are also parents to sons Eduardo "Edu" Pao Lucas, 20 months, Romeo Alejandro David, 3½, Leonardo Ángel Charles, 5, and Rafael Thomas, 6, and daughter Maria Lucia Victoria, 15 months. Alec is also dad to 26-year-old daughter Ireland Baldwin, whom he shares with ex-wife Kim Basinger.
Hilaria Baldwin Instagram
The 64-year-old actor opened up about why he and Hilaria keep growing their family on Instagram in April.
"People ask why. This is why. Being a parent is the ultimate journey," the actor captioned a clip of María Lucía.
The month prior, the couple spoke with PEOPLE about their upcoming addition to the family.
"We have 'somos un buen equipo' engraved on our wedding bands. We say that to each other all the time at home — that we're a good team," the couple said in an exclusive statement. "One of the most beautiful things my children have experienced with a big family is how the heart can grow with every new sibling."
"Our capacity to love continues to expand and we can't wait to embrace our new little one this fall!" they added.