It happened about six o'clock Sunday evening on North Columbia in Plainview.
According to witnesses Juan Castaneda was observed ramming his Chevy pick-up into a Pontiac Grand-Am driven by Vivian Castaneda.
Police say the pick-up truck struck the car with such force it caused it to veer off the road and strike a pole.
The pick-up also left the roadway and came to rest on top of the Grand-Am.
Vivian Castaneda and her unborn child were pronounced dead at a hospital in Lubbock.
Juan Castaneda is behind bars at the Hale County Jail tonight charged with murder.