Two cars have collided at the intersection of Millers Road and Bellevue Road in Brookfield.
A police spokesperson says the crash occurred around 11:47am.
"The crash involved two cars, one of which did not stop. Enquiries are underway to locate that vehicle.
"The car that remained at the scene contained a pregnant woman who is being checked over by ambo."
A SunLive reader says there were ambulance and lots of people.
"There was an ambulance there first then the fire truck came. They seemed to move closer to the Sydenham park past the corner. The ambulance headed there too."