Preterm Birth measures the percentage of births delivered preterm, prior to 37 weeks. Full term is defined as 40 weeks gestation. These data are collected by the CDC from birth certificates as part of the National Vital Statistics System.

Every year there are 500,000 preterm births, roughly 1 of every 8 births. While babies born late-preterm (between 34 and 36 weeks) are usually healthier than babies born earlier; they are 3 times more likely to die in the first year of life than full-term infants.[1] They are also at increased risk of newborn health problems, including breathing and feeding problems. Preterm births are more likely to be low birthweight than full-term births. Some late-preterm births result from early induction of labor or cesarean delivery due to pregnancy complications. However, in some cases, early delivery may occur without good medical justification. Preterm births are estimated to cost $5.9 billion in direct medical costs.[2]