Introduction

Since the publication of the first edition of this text in 1989, a great deal has been written regarding the issues of neonatal asphyxia and hypoxic–ischemic encephalopathy (HIE) in term and near-term infants. These manuscripts have addressed the incidence, etiology, pathophysiology, treatment, and outcome of such patients, often relating outcomes to the development of cerebral palsy (CP) and/or mental retardation in survivors. Much of the understanding of the pathophysiology has been the result of studies carried out in laboratory animals, which have been extrapolated to the human fetus and newborn. Additional studies of complications and outcome have been population-based, comparing the injured infant to carefully selected normal controls. These studies have added a great deal to our understanding of risk factors for brain injury, and have enhanced our ability to predict and to identify patients with increasing accuracy. This has become increasingly important, as newer modalities of treatment have evolved which require more precision in the early identification of these infants so that the validity of these therapies can be ascertained. As can be seen in Chapters 39, 41, and 42, early institution of treatment becomes of paramount importance if an improved outcome is to be achieved.

While some still believe that the major injuries in these patients occur in the intrapartum period, many studies suggest otherwise, and allude to the fact that many of the problems arise antenatally, and may be exacerbated in the intrapartum period.