Intrauterine inflammation at term: a histopathologic study

This study was undertaken to examine the presence of inflammation of the uterine and gestational tissues as defined by histopathology in clinically noninfected women with term gestation and intact fetal membranes and to evaluate its correlation with measured clinical variables and neonatal and maternal clinical outcome. Two hundred sixteen clinically noninfected term parturients who underwent cesarean section with intact membranes were analyzed for the presence of inflammatory lesions of the gestational tissues and uterus. Nine hundred eighty-one histologic samples were studied, including 212 samples from both chorion membranes and umbilical cords, and 209 placental, 192 myometrial, and 156 decidual samples. In 208 (96%) cases, either amniotic fluid (AF) or endometrial swab samples were cultivated for bacteria. In 148 (69%) cases, the AF leukocyte count was analyzed by the Gram stain method, and in 77 (36%), AF leukocyte esterase activity (LEA) was evaluated. Leukocytic infiltrations were present in samples from 41 (19%) women, varying from 2% to 10% in the different anatomic sites examined. However, after onset of labor, low-grade decidual inflammation was observed in 29% of cases. Cervical dilation (odds ratio, 4.7; 95% confidence interval, 2.4 to 9.3; P < .00003) and meconium-stained AF at the operation (odds ratio, 5.3; 95% confidence interval, 2.2 to 12.5; P < .00015) were associated with the histologic inflammatory lesions observed in decidual samples, independently of AF or endometrial microbial detection, AF leukocytes, or LEA.