Quantitative Assessment of Collagen Remodeling during\na Murine Pregnancy

Uterine cervical\nremodeling is a fundamental feature of pregnancy,\nfacilitating the delivery of the fetus through the cervical canal.\nYet, we still know very little about this process due to the lack\nof methodologies that can quantitatively and unequivocally pinpoint\nthe changes the cervix undergoes during pregnancy. We utilize polarization-resolved\nsecond harmonic generation to visualize the alterations the cervix\nextracellular matrix, specifically collagen, undergoes during pregnancy\nwith exquisite resolution. This technique provides images of the collagen\norientation at the pixel level (0.4 μm) over the entire murine\ncervical section. They show tight and ordered packing of collagen\nfibers around the os at the early stage of pregnancy and their disruption\nat the later stages. Furthermore, we utilize a straightforward statistical\nanalysis to demonstrate the loss of order in the tissue, consistent\nwith the loss of mechanical properties associated with this process.\nThis work provides a deeper understanding of the parturition process\nand could support research into the cause of pathological or premature\nbirth.