Perinatal Pathology and Fetal Medicine

Abstract

Fetal medicine is a multidisciplinary field in which data collected from multiple sources to formulate the best care plan possible. This issue of the Journal of Fetal Medicine (JFM) highlights perinatal pathology, a core component in any well-designed fetal medicine program. Gross and microscopic studies of the placenta and embryo, fetus, or neonate can provide invaluable insights into the etiology and/or pathogenesis of a wide range of conditions with important implications, particularly those related to genetic counseling and the management of future pregnancies. The practice of perinatal pathology requires a thorough understanding of normal developmental anatomy, ability to recognize and document deviations from the norm, knowledge of common congenital disorders, and skilled utilization of other informational and/or laboratory resources to investigate rare conditions. Proficiency in this subspecialty requires years of practice and continued education with regard to newly defined syndromes, advances in molecular genetics, and human embryology. Perinatal pathology is ideally practiced by a pathologist specifically trained to examine products of conception. However, in many communities, by necessity, the role is filled by a geneticist, obstetrician, or other professional, whose formal training may not have included pathology per se. The articles in this issue are written by experts in the field of perinatal pathology to explicitly review some fundamental practice guidelines and illustrate basic principles that guide the subspecialty. Topics were chosen with other members of the fetal medicine team in mind, including nonexperts who may be called upon to perform some type of perinatal pathology examination. Collectively, these papers provide a good overview of how to approach different aspects of the exam, the type of information that can be collected with systematic analyses, and how this data can be integrated with other laboratory studies and correlated with clinical findings. Examination of the placenta is a cornerstone of perinatal pathology, especially when a pregnancy is complicated by multiple gestation, premature delivery, intrauterine growth restriction, infection, or fetal demise. In his article on ‘‘Placental Gross Examination’’, Dr. Sunil Jaiman describes a logical step-by-step approach to examination of this organ, explaining how gross findings are used to direct microscopic evaluation. Dr. Jaiman emphasizes findings that may explain fetal demise. A common cause of fetal demise and other adverse pregnancy outcome is fetal thrombotic vasculopathy (FTV), which is the subject of the scholarly contribution by Drs. Marsden and Comstock. Readers learn how FTV is recognized and the challenges associated with distinguishing antemortem FTV from nonspecific postmortem histopathological vascular changes. They summarize conflicting published data regarding the relevance of hereditary thrombophilia to the pathogenesis of FTV and the role for a thrombophilia workup in affected pregnancies. Placental mesenchymal dysplasia is less common than FTV and less well known to many clinicians, but has garnered increased attention recently because of its sonographic confusion with molar pregnancy, clinical associations with assisted reproduction technology, and Beckwith–Wiedemann syndrome, and fascinating genetic findings. Dr. Linda Ernst’s comprehensive review of placental mesenchymal dysplasia (PMD) discusses all of these aspects. Readers will finish this paper prepared to consider & Raj P. Kapur raj.kapur@seattlechildrens.org