Prediction of chorioamnionitis in cases of intraamniotic infection by ureaplasma urealyticum in women with very preterm premature rupture of membranes or preterm labour.

OBJECTIVES: First, to determinate the frequency of chorioamnionitis and funisitis in cases of intramniotic detection of Ureaplasma urealyticum. Second, to assess the predictive capability of some biological markers in the amniotic fluid of these women to predict histological inflammation.

SUBJECTS AND METHODS: We prospectively studied 20 cases of women with premature rupture of membranes or preterm labour (PROM) or preterm labour and intraamniotic detection of Ureaplasma urealyticum. Gestational age at admission was 26.74 ± 2.53 weeks. Amniotic fluid concentrations of IL18, IL 2, IL4, IL6, IL10, IL12, TNF-alpha, IFN-g, and MMP-8 were measured by the Multiplex method. Amniotic fluid glucose and leukocyte count were also measured by standard methods. Placental detailed histological studies were performed. Student's t-test, forward stepwise conditional binary logistic regression analysis and ROC curves were used.

RESULTS: Histological chorioamnionitis was present in 45% of cases (9/20) and funisitis just in 15% (3/20). Interleukins 6, 8, 12, MMP-8, and leukocyte count were significantly elevated in cases of histological inflammation, defined as choriamnionitis or chorioamniotis + funisitis (p = .007, .03, .01, .03, .03, respectively) while glucose was decreased (p = .04). Binary logistic regression for the prediction of inflammation showed a high predictive value (R2  = .66, p = .002) including in the equation only the IL6 value.

CONCLUSIONS: A significant percentage of cases with intraamniotic detection of Ureaplasma urealyticum shows no pathological signs of histological inflammation. Concentration of Interleukin 6 in amniotic fluid can be useful for the diagnosis of subclinical chorioamnionitis in these cases.