Short- and Long-Term Consequences of Late-Preterm and Early-Term Birth.

Late-preterm (34-36 weeks) and early-term (37-38 weeks) newborns were, up until recently, erroneously categorized as low-risk and were conflated with full-term (39-40 weeks) deliveries. However, emerging evidence refuted this notion and demonstrated that late-preterm and, to a lesser extent, early-term newborns have a significantly higher risk of experiencing various neonatal morbidities, including respiratory distress syndrome, transient tachypnea of the newborn, pneumonia, jaundice, hypoglycemia, and breastfeeding difficulties, compared to their full-term counterparts-reflecting their relative physiologic and developmental immaturity. Recent evidence also unravels the lingering adverse effects of late-preterm and early-term delivery up until mid-adulthood, with the increased susceptibility of these newborns to neurodevelopmental delays, behavioral and neuropsychiatric problems, and adult chronic diseases. Moreover, apart from increased neonatal and infant mortality rates, these newborns continue to encounter a heightened risk of mortality even up to mid-adulthood. As the full spectrum of the complications these newborns face is gradually being unveiled, this review presents and discusses the current knowledge base, identifies gaps in the literature, and highlights future research implications.