The event is named for the 24-year-old pop star who drew criticism when she was photographed with her baby son, Sean Preston, sitting on her lap as she drove, and later, in a car seat facing forward rather than facing backward, which some safety regulations say is best.
Fans attending Friday night's game will receive information on baby car seat safety and a chance to win a free car seat from the American Automobile Association.
Those who dress as a baby, bring a baby toy or bring their baby — a child under the age of 4 — get in free.
The event features a "special guest" who sings and dances, Bears spokesman Joe Montefusco said Thursday. He would not name the guest.
The Bears, perhaps fittingly, play a team called the Road Warriors.
Spears has defended her parenting skills and has cautioned against judging her. "I did it with my dad. I'd sit on his lap and I drive," the Louisiana native has said of the February incident. "We're country."
The singer is expecting her second child with husband and aspiring rapper Kevin Federline this fall. Sean Preston was born last September.