The Erbium-YAG laser was used to produce narrow wounds of defined depth in term amniochorion. The charring effect of the laser meant that sites could be readily localized in histological sections. During brief post-wounding incubations, sliding displacement of the amnion relative to the chorion occurred through the plane of the spongy layer. This suggests a possible short-term mechanism whereby a spontaneous rupture could be sealed in vivo.