The Future of Very Preterm Infants:  Learning From the Past

What is the long-term future of infants who are born after very short gestations (<33 weeks) compared with infants born at term? As the article by Swamy and colleagues¹ in this issue of JAMA suggests, the experience of a population of very preterm infants in Norway offers some insights. This retrospective cohort included 1.1 million singleton births in Norway from 1967 through 1988 occurring at 22 or more weeks of gestation and weighing 500 g or more. The investigators assessed the perinatal, childhood, and adolescent mortality of this cohort through 2002 and followed a subset of survivors for educational and reproductive outcomes through 2004. They found that male and female very preterm offspring (born at 22-32 weeks of gestation) had a higher risk of mortality from the perinatal period through age 5 years compared with their term counterparts (born at 37-42 weeks of gestation). The highest mortality rate occurred at delivery and at the shortest gestations. The rate of stillbirths at 22 to 27 weeks of gestation was 53.1%, whereas at term the rate was 0.38%. Survival rates increased from infancy to late childhood.