Placental pathology: a neglected link between basic disease mechanisms and untoward pregnancy outcome.

The long-term goal of examining placentas from patients with adverse pregnancy outcomes has always been to understand better the basic underlying disease processes involved. Through a consideration of clinical, sonographic, laboratory, and anatomic pathological data this goal is now being realized. Placental pathology in the following four clinical scenarios is reviewed: preterm labor, intrauterine growth retardation, intrauterine fetal demise, and birth asphyxia with long-term adverse sequela.