Association of Placental Pathology with Physical and Neuronal Development of Infants: A Narrative Review and Reclassification of the Literature by the Consensus Statement of the Amsterdam Placental Workshop Group

Abstract

The placenta is the largest fetal organ, which connects the mother to the fetus and supports most aspects of organogenesis through the transport of nutrients and gases. However, further studies are needed to assess placental pathology as a reliable predictor of long-term physical growth or neural development in newborns. The Consensus Statement of the Amsterdam Placental Workshop Group (APWGCS) on the sampling and definition of placental lesions has resulted in diagnostic uniformity in describing the most common pathological lesions of the placenta and contributed to the international standardization of descriptions of placental pathology. In this narrative review, we reclassified descriptions of placental pathology from previously published papers according to the APWGCS criteria and comparatively assessed the relationship with infantile physical and/or neural development. After reclassification and reevaluation, placental pathology of maternal vascular malperfusion, one of the APWGCS criteria, emerged as a promising candidate as a universal predictor of negative infantile neurodevelopmental outcomes, not only in term and preterm deliveries but also in high-risk groups of very low birthweight newborns. However, there are few studies that examined placental pathology according to the full categories of APWGCS and also included low-risk general infants. It is necessary to incorporate the assessment of placental pathology utilizing APWGCS in the design of future birth cohort studies as well as in follow-up investigations of high-risk infants.

Keywords: infants; neural development; nutrients transport; pathology; physical development; placenta.

Figure 1

Representative pathological findings by HE staining of placentas in accordance with the categories of the Consensus Statement of the Amsterdam Placental Workshop Group (APWGCS). (A) ‘Accelerated villous maturation’; the yellow arrow indicates increased placental villi with the focal formation of tight adherent villous clusters with syncytial knots. (B) ‘Decidual vasculopathy’; the yellow arrow indicates the fibrinoid necrosis of decidual vessels. (C) ‘Distal villous hypoplasia’; the yellow arrow indicates thin and elongated villi surrounding the stem villi. (D) ‘Thrombus’. (E) ‘Avascular villi’; the yellow arrow indicates a villus with hyalinized stroma, which is devoid of vessels. (F) ‘MIR’; the infiltration of neutrophils into the chorionic plate. (G) ‘FIR’; the infiltration of neutrophils into the umbilical artery. (H) ‘VUE’; the yellow arrow indicates lymphohistiocytic inflammation predominantly in the stroma of the terminal villi.