Hoag Memorial Hospital Presbyterian, one of the largest and most respected facilities in Orange County, needed to move quickly. A big insurer had warned that its maternity costs were too high and it might be cut from the plan's network. The reason? Too many cesarean sections. "We were under intense scrutiny," said Dr. Allyson Brooks, executive medical director of Hoag's women's health institute. The C-section rate at the time, in early 2012, was about 38 percent. That was higher than the state average of 33 percent and above most others in the area, according to the California Maternal Quality Care Collaborative, which seeks to use data to improve birth outcomes.