According to the Georgia State Patrol, Lynch was driving under the influence on Christmas Day in a 1996 Ford Bronco going eastbound on Georgia Highway 53. The vehicle ran off the road on the right side, re-entered the roadway and struck a 2006 Kia Spectra head-on.
Authorities said The Kia was being driven by April Nacoale Winters, 40, of Cartersville, who was one of the fatalities.
The other two fatalities were Taneka Ackies, 21, and Niyla Ackies, 27 days, both of Cartersville.
According to authorities, Crystal Lynch, 35, of Calhoun, and two passengers in the Kia, Alexis Gardner, 20, and Ratanza Winters, 20, both of Cartersville, initially went to Floyd Medical Center by ground and were later transferred to Erlanger Medical Center.
Authorities said Gardner was six months pregnant and had to have an emergency Caesarean section, but the baby later died.
An Erlanger spokeswoman said Thursday, Lynch and Gardner were listed in critical condition, and Ratanza Winters was listed in fair condition.
According to authorities Brent Lynch was treated at Hamilton Medical Center in Dalton. After he was released he was booked into the Gordon County jail Wednesday at 6 p.m.
According to authorities Lynch has been charged with three counts of first degree vehicular homicide, one count of feticide by vehicle, D.U.I, two counts of serious injury by vehicle, driving on the wrong side of the road, and failing to maintain lane.