Does an intracervical infection influence the fibrinolytic activity and the collagen content of the fetal membranes? A study of ascending infections in pregnant ewes

Apart from solely mechanical explanations, premature rupture of the membranes (PROM) has been suggested to be caused by an ascending infection. In order to investigate the role of infection in the mechanism of PROM, pregnant ewes were experimentally inoculated endocervically with either Bacteroides fragilis, Streptococcus intermedius or group B streptococci. These microorganisms were previously reported to be implicated in PROM in humans. The present investigation concerns the possible effect of an experimentally induced ascending infection on the collagen content and fibrinolytic activity (FA) of the fetal membranes. No relationship was observed between an ascending infection during pregnancy and the collagen content of the fetal membrane specimens. It was concluded that changes in the collagen content bear no etiological significance in the mechanism of premature membrane rupture irrespective of an ascending infection's being present or not. Concerning FA in only one case, experiencing a Strept. intermedius amnionitis, was an elevated FA value observed. This finding indicates that the involvement of FA in the process of membrane rupture following ascending infection during pregnancy cannot be ruled out.