A very pregnant Sandra Amezquita, 44, was thrown to the ground then straddled by a Brooklyn police officer after trying to help her 17-year-old son, Jhohan Lemos, who was being arrested, .
Amezquita is five months pregnant she was thrown down — belly first, straddled and her stomach was pressed into the ground.
The disturbing altercation has prompted an investigation by the NYPD Bureau of Internal Affairs.