Introduction

In the context of untoward fetal and/or neonatal outcome, the purpose of performing placental pathology is to identify responsible mechanism(s) and their timing with respect to stillbirth or delivery. Placental pathologic correlates of intrauterine stressors resulting in fetal and neonatal brain injury are fairly well defined. The dilemma arises not in identifying placental abnormalities but in their interpretation in the clinical context. This is due primarily to a paucity of prospective studies directly linking specific clinical abnormalities with placental pathology, which are rarely done in humans as they present practical and ethical problems. Also, there are relatively few animal models of induced pregnancy disorders that have analyzed placental correlates. Instead, associations have largely arisen from clinically or pathologically driven retrospective studies. As a result, in an individual case there is room for interpretation with respect to the likelihood of abnormal placental findings in contributing to or causing untoward neurologic outcome. The benefit of gaining a body of experience in examining placentas and recognizing patterns of association narrows an individual pathologist's interpretive variability. Still, there remains scant bedrock of experimental data upon which to build clinicopathologic interpretation. Consensus provides a surrogate mode of demonstrating confidence in placental interpretation, and to this end two coauthors have collaborated in constructing this chapter. The information and opinions expressed herein reflect our collective experience and understanding of the relationship between placental pathology and intrauterine stressors leading to clinically determined fetal and neonatal brain injury.