Matthew Gaudreau's wife just gave birth to their son ... four short months after he and his brother Johnny were killed by an alleged drunk driver.
Madeline Gaudreau announced the news on Instagram early Sunday morning ... sharing a photo of their baby boy holding tightly to her hand -- and revealing she named him Tripp.
In her caption, Madeline writes Tripp is "Mommy & Daddy’s world" ... keeping Matthew's presence within the family alive. BTW, Matthew helped choose the name before he passed, it seems.