Late preterm infants: severe hyperbilirubinemia and postnatal glucose homeostasis.

The identification of late preterm infants as a high-risk group of infants has been an important public health breakthrough. These infants have suffered a relative 'silent morbidity and mortality' before the recognition that they have unique physiology and risks. These infants represent almost three-fourths of all premature births in the United States. Many of these infants, because of their birthweight and appearance, have been treated in Well Baby Nurseries and even discharged by 48 h of birth despite specific unidentified or unappreciated risks that have led to their readmission and possible severe morbidities or even death. Two common problems for these infants include neonatal hypoglycemia and severe hyperbilirubinemia. The definition of hypoglycemia remains controversial but is nonetheless a problem of increasing frequency in these infants.