Progestogens for Prevention of Preterm Birth Executive Summary

Birth before completion of 37 weeks of pregnancy is considered preterm. These early births are associated with more than 85 percent of all perinatal morbidity and mortality and are the leading cause of infant mortality and long-term disability.1-2 Each year in the United States more than 475,000 infants are born preterm representing 12.5 percent of live births.3 Efforts to reduce preterm birth have been largely unsuccessful, with a 20 percent relative increase since 1990 in the proportion of births in the United States that are preterm.2