New Insights on the Biomechanics of the Fetal Membrane.

During pregnancy, the Fetal Membrane (FM) is subjected to mechanical stretching that may result in preterm labor. The structural integrity of the FM is maintained by its collagenous layer. Disconnection and reconnection of molecular bonds between collagen fibrils is the fundamental process that governs the irreversible mechanical and supramolecular changes in the FM. At a critical threshold strain, bundling and alignment of collagen fibrils alter the super-molecular structure of the collagenous layer. Recent studies indicate that these changes are associated with inflammation and/or expression of specific proteins that are known to be related to uterine contractions and labor. The potential healing of stretching-induced damages in the FM by mediators involved in mechano-transduction is discussed.