title: Computational modeling of the structure-function relationship in human placental terminal villi.
abstract: Placental oxygen transport takes place at the final branches of the villous tree and is dictated by the relative arrangement of the maternal and fetal circulations. Modeling techniques have failed to accurately assess the structure-function relationship in the terminal villi due to the geometrical complexity. Three-dimensional blood flow and oxygen transport was modeled in four terminal villi reconstructed from confocal image stacks. The blood flow was analyzed along the center lines of capillary segments and the effect of the variability in capillary diameter, tortuosity and branching was investigated. Additionally, a validation study was performed to corroborate the simulation results. The results show how capillary variations impact motion of the fetal blood, and how their bends and dilatations can decelerate the flow by up to 80%. Vortical flow is also demonstrated not to develop in the fetal capillaries. The different geometries are shown to dictate the transport of gases with differences of over 100% in the oxygen flux between samples. Capillary variations are key for efficient oxygen uptake by the fetus; they allow the blood to decelerate where the villous membrane is thinnest allowing for a better oxygenation, but also by reducing the vessel diameter they carry the oxygenated blood away fast. The methodology employed herein could become a platform to simulate complicated in-vivo and in-vitro scenarios of pregnancy complications.
authors.affiliation: Nanoscience Centre, Department of Engineering, University of Cambridge, Cambridge, CB3 0FF, UK; Centre for Trophoblast Research (CTR), Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, CB2 3EG, UK.
authors.forename: R
authors.initials: R
authors.lastname: Plitman Mayo
authors.affiliation: Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge, CB3 0WA.
authors.forename: J
authors.initials: J
authors.lastname: Olsthoorn
authors.affiliation: Centre for Trophoblast Research (CTR), Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, CB2 3EG, UK; Department of Obstetrics & Gynaecology, University of Cambridge, Cambridge, CB2 0SW, UK.
authors.forename: D S
authors.initials: DS
authors.lastname: Charnock-Jones
authors.affiliation: Centre for Trophoblast Research (CTR), Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, CB2 3EG, UK.
authors.forename: G J
authors.initials: GJ
authors.lastname: Burton
authors.affiliation: Nanoscience Centre, Department of Engineering, University of Cambridge, Cambridge, CB3 0FF, UK; Centre for Trophoblast Research (CTR), Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, CB2 3EG, UK. Electronic address: mlo29@cam.ac.uk.
authors.forename: M L
authors.initials: ML
authors.lastname: Oyen
mesh_terms: D002196:Capillaries / Q000502:physiology; D002824:Chorionic Villi / Q000098:blood supply / Q000502:physiology*; D003198:Computer Simulation; D005260:Female; D005333:Fetus / Q000098:blood supply; D006801:Humans; D008954:Models, Biological; D010100:Oxygen / Q000502:physiology; D011247:Pregnancy; D012039:Regional Blood Flow
chemical_list: D010100:Oxygen
keywords: Blood flow; Modeling; Oxygen transport; Placenta; Terminal villi