Describing the Increase in Preterm Births in the United States, 2014-2016.

Infants born before 37 weeks of gestation, commonly referred to as preterm, are at greater risk of early death than those born later in pregnancy and can suffer numerous health and developmental problems, especially at earlier gestational ages (1-3). The incidence of preterm birth in the United States rose from the early 1980s through 2006 but declined from 2007 through 2014 (4-6). Recent data for 2014-2016, however, indicate that the preterm rate is on the rise again (6). This report describes trends in total, early (less than 34 weeks), and late (34-36 weeks) preterm births by plurality, race and Hispanic origin of the mother, and state of residence during 2014-2016.