Using the obstetric research to develop their underlying assumptions, investigators created a decision-analytic model to compare outcomes in a theoretical population of 3.2 million healthy, low-risk women with no prior cesareans—this being the number of such women giving birth in the U.S. each year—based on whether they were admitted to the hospital at less than 4 cm dilation or at 4 or more cm dilation. They found that delaying admission until active labor would result in 67,200 fewer cesareans and 10 fewer maternal deaths while having no effect on fetal deaths.