Introduction

The placenta (derived from the Latin word translating as ‘flat cake’) provides oxygen, nourishment, and protection to the fetus. It also has excretory and endocrine functions. Numerous hormones such as human chorionic gonadotropin, progesterone, estrone, estradiol, estriol, and human placental lactogen are secreted by the placenta. Thus, the trophoblast contributes significantly to the hormonal milieu during pregnancy. Examination of the placenta in cases of poor pregnancy outcome and certain maternal disorders provides documentation and information useful to the obstetrician and neonatologist. Pathologic lesions of the placenta can be broadly classified into four types depending on their clinical relevance:

(1) Lesions responsible for fetal or neonatal morbidity and/or mortality (infarction, infection, abruption, etc.);

(2) Lesions related to premature delivery (chorioamnionitis, abruption, etc.); (3) Lesions that are likely to modify immediate management of the mother (e.g.