A systematic review of severe morbidity in infants born late preterm

Abstract

Late-preterm infants (34 weeks 0/7 days-36 weeks 6/7 days' gestation) represent the largest proportion of singleton preterm births. A systematic review was performed to access the short- and/or long-term morbidity of late-preterm infants. An electronic search was conducted for cohort studies published from January 2000 through July 2010. We identified 22 studies studying 29,375,675 infants. Compared with infants born at term, infants born late preterm were more likely to suffer poorer short-term outcomes such as respiratory distress syndrome (relative risk [RR], 17.3), intraventricular hemorrhage (RR, 4.9), and death <28 days (RR, 5.9). Beyond the neonatal period, late-preterm infants were more likely to die in the first year (RR, 3.7) and to suffer from cerebral palsy (RR, 3.1). Although the absolute incidence of neonatal mortality and morbidity in infants born late preterm is low, its incidence is significantly increased as compared with infants born at term.