Which is more important for the intensity of intra-amniotic inflammation between total grade or involved anatomical region in preterm gestations with acute histologic chorioamnionitis?

OBJECTIVE There is no data on which is more important for the intensity of intra-amniotic inflammation (IAI) between total grade or involved anatomical region in acute histologic chorioamnionitis (acute-HCA) of preterm-gestations. The objective of current study is to examine this issue. METHODS The intensity of IAI was measured by amniotic fluid (AF) white blood cell (WBC) count and matrix metalloproteinase-8 (MMP-8) concentration in 225 singleton preterm-gestations (<36 weeks) who had acute-HCA including chorio-decidua involvement and delivered within 5 days of amniocentesis. Acute-HCA was defined in the presence of acute inflammatory changes in each anatomical region (i.e., chorio-decidua, amnion or chorionic plate). Patients were divided into 6 groups according to total grade (i.e., 1-6) and the presence or absence of chorio-decidua restriction (i.e., chorio-decidua restriction vs. extension beyond chorio-decidua) of acute-HCA. RESULTS There was no significant difference in a median AF WBC and MMP-8 between the two groups (group-1, cases with total grade 1 vs. group-2, cases with total grade 2) among cases with chorio-decidua restriction (each for P>0.05) and between the four groups (group-3, cases with total grade 2 vs. group-4, cases with total grade 3 vs. group-5, cases with total grade 4 vs. group-6, cases with total grade 5-6) among cases with extension beyond chorio-decidua (each for P>0.05). However, group-3 (cases with extension beyond chorio-decidua) had a significantly higher median AF WBC and MMP-8 than group-2 (cases with chorio-decidua restriction) among cases with total grade 2 (each for P<0.05). CONCLUSION Involved anatomical region is more important than total grade for the intensity of IAI in acute-HCA of preterm-gestations.