Polarimetric microscopy is a powerful tool for assessing fiber orientation and reorganization during various biological processes. Collagen fiber remodeling in the uterine cervix is a vital process in pregnancy that enables timely fetal delivery, yet the spatio-temporal details of this process remain poorly understood. In this study, we measured collagen fiber reorganization at different stages of murine gestation and at various cervical depths. We employed two polarization-sensitive techniques, polarization-resolved Second Harmonic Generation (p-SHG) microscopy to specifically detect fibrillar collagen and analyze its orientation with sub-micrometer resolution, and Mueller matrix microscopy to achieve a large field of view but low-resolution imaging of the uterine cervix. Whole cervical transverse sections were imaged, and an analysis pipeline was implemented to quantify collagen distribution. p-SHG results show, for the first time, that collagen content is higher in the lower cervix and increases significantly throughout gestation. We also observed a notable increase in pore size and density during gestation, especially in the upper cervix. Most importantly, by analyzing polarimetric orientation maps, we found that collagen fiber disorganization occurs progressively, starting from the lower cervix at gestation day 12 and extending throughout the entire cervix by day 15. In addition, we demonstrated that the temporal dynamics of disorganization could also be tracked using Mueller matrix imaging, a method suitable for clinical deployment that has substantially lower spatial sensitivity. These findings highlight the potential of advanced polarimetric imaging to enhance our understanding of fibrous tissue remodeling and open new avenues for diagnosing gestation-related issues, such as premature birth.
