Mechanical Properties of Spontaneously and Artificially Ruptured Human Amnion

The chorioamnion (CA) is the sac that surrounds the fetus in utero. It is comprised of two layers: the inner fibrous amnion, mainly composed of collagen and the thick cellular chorion¹. CA is an exceptionally tough material, yet is the only material in the human body that is designed to mechanically fail². Past studies have focused on the events associated with rupture such as the puncture force^3,4,5,6,7, delamination stress^8,9, elastic stiffness^10,11, failure energy^7,10,12, and failure force^10,11. However, few have investigated pre-failure behavior^4,13 to understand contributions to different modes of CA rupture.