Matthew Gaudreau's Wife Gives Birth to Son Four Months After Tragic Death

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.

As you know ... Matthew and Johnny were riding bicycles just after 8 PM ET in Oldmans Township, New Jersey -- when an alleged drunk driver hit them from behind.

Cops say the two sustained major injuries and died at the scene ... and, a man named Sean Higgins was arrested on two counts of death by auto.

Body cam footage taken shortly after the Gaudreaus were hit shows officers putting Higgins through a series of field sobriety tests before slapping cuffs on him.

Matthew's wife revealed how excited he was to be a father during her eulogy days after he was killed ... saying "The moment we found out about our son, Tripp, it consumed his every day. He was downloading apps, ordering books, finding the best diaper brands. Making sure I had the best vitamins and asking for tips from John."

Matthew was 29 and Johnny was 31.