Macroscopic lesions of maternal and fetal vascular malperfusion in stillborn placentas: Diagnosis in the absence of microscopic histopathological examination

Interdependence of placenta and fetal cardiac development

The placenta and fetal heart undergo development concurrently during early pregnancy, and, while human studies have reported associations between placental abnormalities and congenital heart disease (CHD), the nature of this relationship remains incompletely understood. Evidence from animal studies suggests a plausible cause and effect connection between placental abnormalities and fetal CHD. Biomechanical models demonstrate the influence of mechanical forces on cardiac development, whereas genetic models highlight the role of confined placental mutations that can cause some forms of CHD. Similar definitive studies in humans are lacking; however, placental pathologies such as maternal and fetal vascular malperfusion and chronic deciduitis are frequently observed in pregnancies complicated by CHD. Moreover, maternal conditions such as diabetes and pre-eclampsia, which affect placental function, are associated with increased risk of CHD in offspring. Bridging the gap between animal models and human studies is crucial to understanding how placental abnormalities may contribute to human fetal CHD. The next steps will require new methodologies and multidisciplinary approaches combining innovative imaging modalities, comprehensive genomic testing, and histopathology. These studies may eventually lead to preventative strategies for some forms of CHD by targeting placental influences on fetal heart development.

Stillbirth and the placenta

Stillbirth affects a large proportion of pregnancies world-wide annually and continues to be a major public health concern. Several causes of stillbirth have been identified and include obstetrical complications, placental abnormalities, fetal malformations, infections, and medical complications in pregnancy. Placental abnormalities such as placental abruption, chorioangioma, vasa previa, and umbilical cord abnormalities have been identified as causes of death for a significant proportion of stillbirths. In the absence of placental abnormalities, the gross and histologic changes in the placenta in stillbirth are found when secondary to other etiologies. Here we describe both gross and histologic changes of the placenta that are associated with stillbirth.