The charity aims to make pregnancy and childbirth safer for mothers around the world by linking mothers to providers of care.
Turlington has two children with her husband Edward Burns - Grace, 12 and Finn, nine.
Having already run the London marathon in April 2015 in aid of the charity, Turlington also recently announced she will be doing the Boston marathon.
Turlington set up Every Mother Counts after having endured a childbirth complication herself. She had a postpartum hemorrhage when delivering her first daughter.
She said she later learned hemorrhages are a leading cause of maternal deaths globally, which made her want to help other mothers around the world.
Two years after her daughter was born, Turlington and her mother travelled with the humanitarian organisation Care to visit El Salvador.
She told FastCompany: "I was pregnant with my son Finn, and we were touring a village where women received prenatal care in a makeshift clinic set up at their water source.
"That’s when it occurred to me that if I’d had my birth complication in that village, I probably would have died.
"I came home from that trip thinking about how I could make a difference for mothers in countries where lack of access to health care and other issues prevent them from getting the essential life-saving care they need."
She went on to launch her charity in 2010.