Interdependence of placenta and fetal cardiac development

Abstract

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.

Figure 1.

Overlapping timeline of fetal cardiac and placental development. Q_s: systemic blood flow; Q_p: pulmonary blood flow; pc: post conception

Figure 2.

Placental pathologies commonly associated with fetal congenital heart disease. Green: maternal vascular malperfusion, including retroplacental hemorrhage (A), infarcted villi (B), and intervillous fibrin (C); Blue: fetal vascular malperfusion, including avascular villi (D), thrombosis (E), stromal-vascular karyorrhexis (F); Yellow: chronic deciduitis (G).