Cervical ureaplasma colonization affects intraamniotic inflammation in preterm labor with intact membrane: a cohort study

Background: A causative role between cervical ureaplasma colonization and adverse outcomes during pregnancy has remained controversial. We investigated whether cervical ureaplasma colonization affects the biochemically or histologically intraamniotic inflammation in preterm birth.Methods: Amniotic fluid was retrieved during delivery. Various chorioamnionitis-related cytokines (interleukin (IL)-1β, -6, -8, -10, and tumor necrosis factor-α) and regulators (matrix metalloproteins (MMP)-8 and MMP-9) were measured with Human Magnetic Luminex screening assay. We tested cervical swab specimens using real-time polymerase chain reaction assays for the detection of ureaplasma spp. colonization. Considering the clinical situation that causes intraamniotic infection, we arbitrarily divided into three categories of preterm labor with intact membrane, preterm premature rupture of membrane (PPROM), and control group with no exposure to preterm labor or preterm premature rupture of membrane.Results: The incidence of cervical ureaplasma colonization was 49.3% (136/276). The incidence of histologic chorioamnionitis was 27.5% (76/200). All differences in cytokines and regulators according to histologic chorioamnionitis were significant. Of the 153 cases that experienced preterm labor with intact membrane, IL-10, MMP-8, and MMP-9 levels in the ureaplasma positive group were significantly higher than those of the ureaplasma negative group. According to logistic regression analysis adjusted to preterm labor with intact membrane, PPROM, and gestational age at delivery, cervical ureaplasma colonization was an independent risk factor of histologic chorioamnionitis (odd ratio: 2.622, 95% confidence interval: 1.443-4.766).Conclusions: Cervical ureaplasma colonization augments biochemically intraamniotic inflammation in preterm labor with intact membrane, and was an independent risk factor of histologic chorioamnionitis.