Mechanical characterization of human umbilical and chorionic plate arteries affected by fetal growth restriction

Fetal growth restriction (FGR) is a pregnancy complication associated with increased perinatal morbidity and mortality in the short term, along with an elevated risk of developing cardiometabolic diseases in the long term. FGR is also associated with vascular dysfunction in the fetoplacental unit. In this work, we develop a clinical study of the fetoplacental circulation (encompassing umbilical and chorionic arteries) under the FGR condition, utilizing a combination of numerical and experimental approaches to quantify biomechanical and morphological characteristics. Placental samples from normal (n=5) and FGR pregnancies (n=5) underwent biomechanical testing (ring opening and ring tensile tests) under physiological conditions. Biomechanical behavior, including material properties and residual stress, was characterized via numerical analysis using a hyper-elastic model and a simulation of the ring-closure process. Morphological analysis, including wall thickness and layer area measurements, was performed to relate structural features to biomechanical behavior. The umbilical and chorionic arteries exhibit distinct responses to FGR: the umbilical artery undergoes both morphological remodeling and changes in biomechanical properties, whereas the chorionic artery primarily shows biomechanical alterations. Overall, this study provides novel biomechanical evidence of the impact of FGR on placental vasculature, highlighting the complex interplay between morphology and mechanics in fetoplacental blood vessels.