Late preterm births--an issue of concern in perinatal care.

“Late-preterm birth” refers to babies born between 34 and 36 weeks of pregnancy. During the past decade in the United States, the delivery of late preterm infants has increased by 14%. There are approximately 500,000 preterm births (births before 37 completed weeks of gestation), which account for 12.5% of live births in the United States annually. Of these preterm births, more than 70% (approximately 350,000 live births) are late preterm. In past, these newborns were labeled “near term,” which implied that they were “almost term,” and hence they were treated as if they were functionally full term because such babies often have a normal birth weight and size. Several studies have shown that late preterm infants are at greater risk than term infants for complications of prematurity, such as feeding difficulty, hypoglycemia, jaundice, temperature instability, apnea, and respiratory distress. In addition, they have increased mortality and higher rates of rehospitalization. These infants also receive intravenous fluids, evaluations for sepsis, and mechanical ventilation more often than matching term infants. Evidence is currently emerging that late preterm infants make up a majority of preterm births, take up significant resources, have increased mortality/morbidity, and may even have long-term neurodevelopmental consequences secondary to their late prematurity. In a recent National Institute of Child Health and Human Development workshop, the experts opined that the phrase “near-term” should be replaced by “late preterm”. It was the belief that the latter would convey the fact that the infants are still preterm, and not “almost term”. In this issue of Pediatrics and Neonatology, Tsai et al have reported a retrospective cohort study of late preterm infants from a medical center in Northern Taiwan. During the years of 2008 and 2009, maternal obstetrical factors, neonatal demographic data, and neonatal complications were compared between full-term and late preterm babies. Not surprisingly, the authors found that late preterm infants also had an increased risk for neonatal morbidities.