An overview of morbidity, mortality and long-term outcome of late preterm birth.

BACKGROUND Preterm birth rate continues to rise around the world mainly at the expense of late preterm newborns, recently defined as births between the gestational age of 34 weeks and 36-6/7 weeks. Late preterm infants are considered to have significantly more short-term and longterm adverse outcomes than term infants. DATA SOURCES Articles concerning morbidity, mortality and long-term outcomes of late preterm infants were retrieved from PubMed/MEDLINE published during the period of 2000-2010. RESULTS Late preterm infants are the fastest growing subgroup of neonates, comprising the majority of all preterm births. Compared with term infants, they have significantly higher risk of morbidity, mortality and adverse long-term outcomes well beyond infancy into adulthood. However, epidemiology and etiology of late preterm births, the magnitude of their morbidity, the long-term life quality, and public health impact have not been well studied. CONCLUSIONS The growing number of late preterm neonates substantiates the importance to better understand and medically approach this special preterm subgroup. A long-term evaluation, monitoring and follow-up of late preterm infants are needed to optimize neonatal care and improve human health status.