The Washington State Patrol received reports Tuesday night of a Dodge Challenger driving erratically on Highway 512 in Lakewood.
Trooper Guy Gill said the driver was a man rushing his pregnant wife to Madigan Army Medical Center.
The baby couldn't wait, so dad pulled over and called 911. His wife gave birth in the car.
Medics arrived to cut the umbilical cord and take the family to the hospital.
Gill told KXLY4's sister station, KOMO, that mom and baby are doing great.