The Preterm Newborn: Morbidity and Mortality—Including a Population-Based Study in Miyazaki Prefecture

Neonatal and perinatal mortality has decreased dramatically in the past few decades. Neonatal mortality rate among all infants accounted for 1.26 per 1000 births in our region between 1998 and 2012. Of these, the mortality rate of preterm infants was 13.0 per 1000, while that of term infants was 0.51 per 1000 births. Compared with term infants, preterm infants have several more serious medical complications throughout the neonatal period, with the possibility of subsequent neurodevelopmental disorders. Most complications during the neonatal period arise from the underdevelopment of organs; these include conditions such as respiratory distress syndrome, chronic lung disease, necrotizing enterocolitis, and patent ductus arteriosus, retinopathy of prematurity, intraventricular hemorrhage, and periventricular leukomalacia. Other complications in the long-term include cerebral palsy and other neurodevelopmental disorders such as mental retardation, epilepsy, and sensory impairment (hearing, vision).