Histobiomechanical Remodeling of the Cervix during Pregnancy: Proposed Framework

Pregnancy involves a gradual change in tissue consistency, where, as gestational age increases a drop in stiffness is noticeable. The extracellular matrix (ECM) of the cervix whose behavior is controlled by the collagen structure is reconfigured, due to hormonal and protein related factors that degraded it. There is an increase in cellular and water content. The collagen maintains a stable percentage, although the synthesis-solubility interaction causes a transformation in the network increasing its diameter and waviness, which destabilizes the mechanical integrity. Further understanding of the remodeling of the cervix becomes a key element in the progress against preterm birth. However, since the woman is in a very delicate state, the available information is scattered. The aim is to provide a framework where the variation of the histological properties is linked with the individual biomechanical evolution of the constituents; therefore a multiscale approach to the problem can be made. The results of different authors were reviewed to obtain values of each component depending on the gestational age, and then they were combined with the mechanical development of each variable obtained from the outputs of numerical simulations of another author. An additive function is proposed, in which the mechanical contribution of each constituent is added to a reference value established for a nonpregnant state. Results show how biochemistry models the mechanical behavior of the tissue through the histology and morphology of the ECM.