David Henrie and wife Maria Cahill expecting baby No. 4

David Henrie and his wife Maria Cahill are expecting another baby, against the odds.

The couple, who share kids Pia, seven, James, five, and Gemma, three, have announced that they are expecting their fourth baby together, a little boy, after struggling to conceive.

"Surprise! Figured this moment was as good as ever to share the good news," Henrie wrote in an Instagram post. "Maria is 5 months pregnant!"

Alongside a selfie with his wife, Henrie explained the "crazy story" behind why becoming parents of four didn't always seem possible.

"Long story short, Maria and I had made peace with the idea that the 'big family' dream might not be God's plan for us," the Wizards of Waverly Place star shared. "Which was fine, we're grateful for our 3."

However, everything changed when they headed to Spain, where Henrie was filming the second season of his adventure documentary series Seeking Beauty.

"Through a miraculous encounter, and the intercession of St Teresa of Avila, we are having our 4th!"

Shortly after Henrie shared the exciting news, Cahill shared her own response on the How I Met Your Mother alum's post.

"Edit: Hi guys, it's Maria here," she wrote under the original caption. "I stole his phone so I could type this.

"While I'm so excited for David to share this with you, I also know that it can be so hard to read pregnancy announcements when you're the one that's

trying to have a baby and nothing seems to be working," she continued.

"I've been there, trying to be happy for others but simultaneously grieving a happiness that I wish could have been mine.

"Know that I see you all, am thinking of you today, and are praying hard for your future pregnancies."