LOW AMNIOTIC-FLUID GLUCOSE-LEVELS ARE A SPECIFIC BUT NOT A SENSITIVE MARKER FOR SUBCLINICAL INTRAUTERINE INFECTIONS IN PATIENTS IN PRETERM LABOR WITH INTACT MEMBRANES

OBJECTIVE: The purpose of this study was to evaluate the ability of a low amniotic fluid glucose level, as defined by previously published t hresholds, to identify a subclinical intrauterine infection in women i n preterm labor with intact membranes. STUDY DESIGN: Amniotic fluid gl ucose levels, amniotic fluid cultures, and placental histologic charac teristics were determined in women with preterm labor (n = 55) and in preterm controls (n = 58). These amniotic fluid glucose levels were co mpared between women with and without intrauterine infection using the Mann-Whitney U test. The sensitivity, specificity, and positive and n egative predictive values for the identification of an intrauterine in fection were determined with four different previously published amnio tic fluid glucose threshold levels and the threshold from receiver-ope rator characteristic curve analysis of the study data. RESULTS: The me dian amniotic fluid glucose level was significantly lower in patients with positive amniotic fluid cultures (intraamniotic infection group) but was not lower in the group of patients with only histologic chorio amnionitis (extraamniotic infection group), compared with noninfected controls. The sensitivity of a low amniotic fluid glucose level to det ect both types of intrauterine infection ranged from 41% to 55%, depen ding on the threshold used. The specificity of a low amniotic fluid gl ucose level to detect an intrauterine infection ranged from 94% to 100 %, the positive predictive value ranged from 86% to 100%, and the nega tive predictive value ranged from 70% to 80% with the same thresholds. CONCLUSION: Low amniotic fluid glucose levels are a specific but not a sensitive marker for either intraamniotic or extraamniotic intrauter ine infections in patients with preterm labor.