The U.S. pre-term birth rate is at a 15-year low but the nation is still getting a "C" on a March of Dimes report card. That's because at 11.5 percent in 2012, America's preterm birth rate is the highest among industrialized countries.
The state with the lowest rate of preterm births was Vermont, at a little under nine percent. Mississippi had the highest rate at about 17-percent. According to the March of Dimes, preterm birth is the leading cause of newborn deaths and babies who survive can face serious health problems.