Physical and geometric determinants of transport in fetoplacental microvascular networks
Journal: Science Advances
Publication Date: 17 April, 2019
Department of: Mathematics
Linking geometry to nutrient exchange in the human placenta
This study demonstrates how complex microstructural features of the human placenta can be analysed to provide new insights into its function in health and disease. Despite recent advances in three-dimensional imaging, we still have limited understanding of the geometric and physical factors that determine the transport of solutes such as oxygen in exchange organs. One such organ is the human placenta, a vital fetal life-support system which contains numerous structures called terminal villi, within which are microscopic fetal blood vessels. In this study, researchers from the University of Manchester show how the irregular internal structure of a terminal villus determines its exchange capacity for a wide range of solutes. Distilling geometric features into two novel parameters, obtained from image analysis and computational fluid dynamics, universal features of the structure-function relationship in the terminal villi are captured using a simple algebraic approximation. The theory reveals intricate transitions between transport regimes at vessel and network levels and offers a new efficient method for multi-scale modelling. The developed predictive framework, based on the understanding of physical processes and carefully defined geometric statistics, provides a promising tool for analysing placental pathologies and could be used to assess transport in other complex microvascular systems.
- Across mammalian species, nutrients are delivered to tissues via complex microvascular networks. The total length of blood vessels in the human placenta reaches over 50 kilometres.
- Placental terminal villi are the primary site of exchange for oxygen and other vital solutes between the mother and her baby. Each terminal villus contains a complex network of fetal capillaries and is surrounded by maternal blood.
- A judicious choice of integral geometric parameters provides a simple and robust tool for characterising the relationship between tissue structure and function.