Contributing factors to preterm pre-labor rupture of the fetal membrane: Biomechanical analysis of the membrane under different physiological conditions

The fetal membranes are a complex biological structure essential for pregnancy, comprising two main layers: the amnion and the chorion. Characterizing each layer from a mechanical perspective is extremely important to understand the rupture process of the membrane at term or preterm. It is still unclear what factors lead to preterm pre-labor rupture of the membrane (PPROM) due to ethical and technical factors associated with in-vivo experimental tests. Numerical simulations may offer some answers, clarifying the biomechanics of the fetal membrane during gestation. This work uses a validated multilayer fetal membrane model to evaluate whether certain physiological conditions occurring during pregnancy contribute to PPROM. The following factors are evaluated: (i) contact conditions between the amnion and the chorion, (ii) normal and abnormal intrauterine pressures, (iii) amnion and chorion thicknesses, and (iv) orientation of the collagen fibers within the amnion layer. Our results show that PPROM might be potentiated under certain physiological circumstances: (i) the existence of interconnection (friction or tied contact) between the two main layers of the fetal membrane increases the stress in the mechanical dominant amnion, (ii) larger intrauterine pressures and (iii) smaller amnion and chorion thicknesses lead to the same increase in stress, and (iv) different off-plane angles of the collagen fibers tend to modify the stress distribution and thickness variation in both layers. •A fetal membrane model was developed using inflation data for the first time.•The multilayer model captured the behavior of each fetal membrane layer.•Several factors may contribute to preterm pre-labour rupture of the membrane.•The amnion is the mechanically dominant layer of the fetal membrane.•The layered model can be integrated into larger models of the gravid uterus.