Their investigation focused on why the maternal mortality rate in the U.S. is going up while it’s going down in nearly every other nation; why African-American women are 3-to-4 times more likely to die than white women; and what’s being done to reverse these dire statistics. The series set off a national conversation at a time when few Americans knew that, in the U.S., even a healthy woman with a perfect pregnancy and good health care risks dying, or nearly dying, in childbirth.