P131 Uterine Arteries Evaluation During Pregnancy: Modeling and Computational Fluid Dynamics Calculations

Abstract

Preeclampsia (PE) affects pregnancy, being one of the main causes of prenatal maternal mortality and morbidity (1). Recent studies show that PE is characterized by a significant reduction on maternal cardiac output and increased peripheral resistance. However, studies on the maternal hemodynamic adaptation during PE and the available information about central maternal hemodynamics are scarce. Our purpose is to develop a computational model to obtain relevant hemodynamic parameters of the maternal circulation, formed by the common iliac (CI), the internal (II) and the external iliac (EI) and the uterine arteries (UA). Model construction requires many approximations and generalizations to optimize numerical calculation of hemodynamic parameters by Computational Fluid Dynamics (CFD), however this is the best representation of maternal circulatory system. Four different models were created to simulate non-pregnant women and 21, 30 and 36 weeks of pregnancy (2). Numerical simulations performed by ANSYS^®-Fluent software correlate blood flow, velocity and arterial pressure, with the variation of uterine morphological data. Calculated flow values on CI and UA to different geometries represent the evolution of arterial system during pregnancy. As the UA suffers higher geometrical transformations during pregnancy, there are a greater increase on blood velocity; blood velocity on the EI increases, remaining almost constant in the CI arteries. The growth on blood flow due to pregnancy development is associated to an augmentation on the arteries’ diameter, which allows the maintenance of blood pressure on UA. This model is suitable to compare wall shear, velocity or flow values associated to PE, measured in clinical context.