A review of feto-placental vasculature flow modelling

Abstract

The placenta provides the vital nutrients and removal of waste products required for fetal growth and development. Understanding and quantifying the differences in structure and function between a normally functioning placenta compared to an abnormal placenta is vital to provide insights into the aetiology and treatment options for fetal growth restriction and other placental disorders. Computational modelling of blood flow in the placenta allows a new understanding of the placental circulation to be obtained. This structured review discusses multiple recent methods for placental vascular model development including analysis of the appearance of the placental vasculature and how placental haemodynamics may be simulated at multiple length scales.

Keywords: Computational modelling; Placenta; Placenta flow modelling; Placental haemodynamics.

Fig. 1

The anatomy of the human placenta identifying the different levels of the placenta broken down as the umbilical, large vessels, maternal and terminal in the review as well as the multiscale covering the combination of these levels.

Fig. 2

The flow diagram of the papers included and excluded in the review. Flowing down into 4 subcategories which were then split as the publications covering the umbilical cord, the top-level vessels such as the chorionic plate vessels, the maternal side of the placenta, multiscale models which cover all of the vessel levels of the placenta and the terminal microscopic level vasculature. Any other papers were categorised as other, the majority being general clinical placental publications.

Fig. 3

A sagittal fetal sub volume approximately 32% the size of the rat placenta 3D reconstructed from Micro-CT imaging modelling the dynamic viscosity reproduced with permission from Bappoo et al. Approximately 4.32 mm in length predicted from 32% of the placentas size [64].

Fig. 4

The multiscale flow model of an ex vivo human placenta from Micro CT quantifying the perfusion. The colour scale shows the volumetric flow in mm3/s reproduced with permission from Byrne et al. Approximate diameter of 20 cm [1].

Fig. 5

Modelling the human terminal villi from confocal laser scanning microscopy, showing the distribution of oxygen flux entering through the capillary at the top and the villous surface at the bottom. Reproduced with permission from Pearce et al. Approximate scale of 30–50 $\mathrm{\mu }$ m [74].