Placental haemodynamics: Transport effects at the organ scale #

Adam M Blakey, Penny Gowland, Paul Houston, Matthew Hubbard, George Hutchinson, Lopa Leach, Reuben O’Dea

12:10 Wednesday in 3Q68.

Part of the Blood and blood vessels session.

Abstract #

The placenta provides nutrients and oxygen to a developing fetus — and is therefore vital to fetal development. It brings maternal and fetal blood close together, allowing nutrients to diffuse across thin separating barriers in the fetal villous tree structure. Structurally, the placenta is divided into placentones: compartments that are partially separated by septal walls.

An approach to modelling maternal blood flow is to treat the fetal villous tree as a porous medium; several authors have utilised this on representative placentone geometries, mainly focusing on arterial supply. However, whilst these simulations are a useful indicator of organ-level behaviour, they fail to describe the effects of the blood flux between neighbouring placentones, as well as neglecting the importance of maternal venous return. In 2020, a new phenomenon was discovered called the placental contraction, which is yet to be mathematically modelled.

I will present some in-silico organ-scale maternal blood flow simulations, using Navier-Stokes and Brinkman equations to model blood flow on representative placental geometries, coupled to a reaction-advection-diffusion equation to model nutrient transport. I will show notable blood flux passing between placentones, the importance of considering maternal venous return paths on the uniformity of oxygen exchange, and that the recently-observed placental contraction phenomenon could be vital in redistributing blood and encouraging venous return.