Introduction

It is established that infants born preterm are at increased risk for a variety of later developmental and health problems when compared to their full-term counterparts [1]. These problems include central nervous system (CNS), sensory, motor, cognitive, learning, behavioral, socioemotional, quality of life, and health concerns [2]. While morbidity is greatest for infants born at the earliest gestational ages, more preterm infants are born closer to term (i.e., 32–36 weeks' gestational age) and these so-called late preterm infants also experience more problems than their full-term peers. However, reported outcomes are based on group probabilities, leaving the outcome of an individual infant less clear.

Numerous biological and environmental factors affect outcomes in addition to birth weight and gestational age. These influences, which are a source of variability, span the pre-, peri-, and postnatal periods and beyond. Among the multiple factors associated with a biological risk condition such as very low birth weight (VLBW, < 1500 g) or extremely low gestational age are: (1) severity of medical complications during the neonatal course (admission status, response to medical interventions, types of medical procedures, duration of hospitalization); (2) sociodemographic factors (socioeconomic status [SES], social support, ethnicity, maternal physical and mental health, environmental exposures to positive and negative experiences); and (3) subsequent illness (rehospitalizations, need for supplemental oxygen, other chronic conditions)[1, 3].

Neurodevelopmental outcome, the focus of this chapter, is increasingly used as the benchmark to determine efficacy of medical interventions or the consequences of being born early [4].