The placenta as a diagnostic tool for the neonatologist

The placenta is a vital organ, shared by a mother and fetus, which houses valuable information on the events and processes occurring before birth. Often these processes can have a negative impact on any or all organ systems, leading to neonatal instability and infant morbidity and mortality. Therefore, the placenta may serve as an important clinical tool for the neonatologist and pediatrician in the diagnosis and management of several complex neonatal diseases. These diagnoses range from neonatal sepsis to congenital infections, sequelae of intrauterine growth abnormalities, neurologic signs, and a wide range of complications accompanying prematurity. The purpose of this review is to provide baseline information on the processes obtainable from the perinatal pathologist’s placental examination. We describe common anatomic and histologic lesions of the placenta that are associated with the aforementioned clinical problems, and describe how such placental findings can help the clinician in routine diagnosis and management. We discuss the current gaps in diagnostic usefulness of the placenta, and how ongoing research is the key to optimizing the placental examination to improve neonatal outcomes.