500: Non-invasive prediction of chorioamnionitis in women with preterm premature rupture of membranes

Abstract

with preterm premature rupture of membranes Kyo Hoon Park, Shi Nae Kim, Eun Ha Jeong, Sung Youn Lee, Aeli Ryu, Kyung Joon Oh Seoul National University College of Medicine, Seoul National University Bundang Hospital, Department of Obstetrics and Gynecology, Seongnam-si, South Korea OBJECTIVE: To develop a model based on non-invasive clinical and ultrasonographic parameters to predict the probability of subsequent chorioamnionitis in women with preterm premature rupture of membranes (PPROM), and to determine if additional invasive test results improve the prediction of subsequent chorioamnionitis based on the non-invasive model. STUDY DESIGN: Transvaginal ultrasonographic assessment of cervical length was performed and maternal serum C-reactive protein (CRP) and white blood cell (WBC) count were determined immediately after amniocentesis in 106 consecutive women with PPROM at 23 0/7-33 6/7 weeks of gestation. Amniotic fluid (AF) obtained by amniocentesis was cultured and interleukin-6 (IL-6) levels and WBC counts were determined. Outcome measures were histologic and clinical chorioamnionitis. The placentas were examined histologically for presence of chorioamnionitis and women were evaluated for evidence of clinical chorioamnionitis. RESULTS: The non-invasive model (model 1) for prediction of histologic chorioamnionitis included serum C-reactive protein (CRP), gestational age, and parity. The model was shown to have an adequate goodness of fit, and the area under the receiver operating characteristic curve (AUC) was 0.756. When adding AF IL-6, AF culture, and AF WBC as invasive markers to the non-invasive model, serum CRP and parity were excluded from the final model (model 2) as not significant, whereas AF IL-6 and gestational age remained in model 2. No significant difference in AUC was found between models 1 and 2. For the outcome of clinical chorioamnionitis, no parameters studied could be identified to predict women at high risk for its development, although the association with AF culture results was borderline statistically significant (P 0.055). CONCLUSION: In women with PPROM, the non-invasive model based on serum CRP, gestational age, and parity was shown to be moderately predictive of developing histologic chorioamnionitis. However, invasive test results did not add predictive information to the non-invasive model in this setting.