Morphologic study of changes of collagenous tissue in the amnion and cervix during prostaglandin-induced abortion and delivery.

Marked dissociation of the cervical collagenous tissue during prostaglandin-induced abortion is well recognized, but the response of collagenous tissue of the amnion to prostaglandin treatment is not known. A morphologic study of amniotic collagenous tissue was performed after prostaglandin-induced abortion and prostaglandin-induced term delivery. The collagenous fibers of the amnion were found to be closely packed with no ground substances and formed in a thick layer. Cervical collagenous tissue of the same patients showed a marked dissociation of fibers and abundant ground substance. The fetus was often delivered within a complete sac at midtrimester. These findings suggest differences in collagenous tissue responses to prostaglandin treatment between the amnion and cervix.