Purpose: to compare the expression of tumor necrosis factor-alpha (TNF-alpha) in ovular membranes with premature rupture (MPR) and with opportune rupture; to verify the association between the expression of the TNF-alpha in ovular membranes and the degree of chorioamnionitis, correlating the expression of the TNF-alpha and the membranes' time of rupture.
Methods: ovular membranes from 31 parturients with MPR, with gestational ages over 34 weeks, and from parturients with opportune membranes' rupture, with gestational ages equal or over 37 weeks. Chorioamnionitis detection has been done by histopathological analysis. The evaluation of the TNF-alpha expression has been done by immune-histochemical technique, using the labile streptavidin-biotin-peroxidase (LSAB) method.
Results: the average rupture time was 16.6 hours. The ratio of the TNF-alpha expression in the Control and Study Groups did not show a significant difference (chi(2)=6.6; p=0.08). In the Study Group, there was no correlation between the degree of chorioamnionitis and the intensity of TNF-alpha expression (Spearman's coefficient (Rs)=0.4; p=0.02).
Conclusions: there was no significant difference between the TNF-alpha expression in ovular membranes with premature or opportune rupture; in the Study Group, there was significant association between TNF-alpha expression and the degree of chorioamnionitis, and there was no association between rupture time and the intensity of TNF-alpha expression.