Modelagem biomecânica do crescimento uterino ao longo da gestação

Abstract

Preterm birth represents a major public health challenge, affecting approximately one in ten births worldwide. During pregnancy, uterine distension generates stresses on the uterine wall, which may promote cervical shortening and/or trigger contractions, thereby increasing the risk of preterm delivery. Despite the growing use of computational models to study pregnancy in recent years, ethical barriers still restrict research on uterine biomechanics throughout gestation. In this context, the present work proposes a biomechanical model to describe uterine evolution from the second trimester onwards. The constitutive model adopted for the uterine body is anisotropic, reflecting the presence of fibers within the uterine tissue, whereas the cervix, when included, is modeled as isotropic. In both cases, the materials are assumed to be incompressible. In the first stage, a simplified geometric model derived from truncated ellipsoids was employed to represent the uterine body. In the second stage, a patient-specific geometry was used, incorporating both the uterine body and cervix. The applied load consisted of intrauterine pressure, representing its progressive increase during pregnancy. The simulation results indicate that the proposed growth model is effective in reproducing growth patterns reported in the literature, such as the simultaneous increase in intrauterine volume and uterine mass. Furthermore, increases in intrauterine diameters and localized thickening in specific regions of the uterine wall were observed, in agreement with clinical data obtained from patients.