A COMPARATIVE-STUDY OF THE DIAGNOSTIC PERFORMANCE OF AMNIOTIC-FLUID GLUCOSE, WHITE BLOOD-CELL COUNT, INTERLEUKIN-6, AND GRAM STAIN IN THE DETECTION OF MICROBIAL INVASION IN PATIENTS WITH PRETERM PREMATURE RUPTURE OF MEMBRANES

OBJECTIVE: Our aim was to compare the value of amniotic fluid tests fo r the detection of microbial invasion of the amniotic cavity and in th e prediction of the amniocentesis-to-delivery interval and neonatal co mplications in patients with preterm premature rupture of membranes. S TUDY DESIGN: Amniotic fluid was obtained by transabdominal amniocentes is from 110 consecutive patients with preterm premature rupture of mem branes. Fluid was cultured for aerobic and anaerobic bacteria, as well as mycoplasmas. Amniotic fluid analysis included a Gram stain examina tion, white blood cell count, and glucose and interleukin-6 determinat ions. Logistic regression and survival techniques (proportional hazard s model) were used for statistical analysis. RESULTS: (1) The prevalen ce of positive amniotic fluid cultures in patients with preterm premat ure rupture of membranes was 38% (42/110); (2) patients with microbial invasion had a shorter amniocentesis-to-delivery interval and a highe r neonatal complication rate than patients with negative cultures; (3) the most sensitive test for the detection of microbial invasion of th e amniotic cavity was amniotic fluid interleukin-6 determinations (cut off 7.9 ng/ml) (sensitivity: for IL-6 80.9%; for white blood cell coun t 57.1 %; for glucose 57.1 %; for Gram stain 23.8%; p < 0.05 for all c omparisons); (4) the most specific test for the detection of microbial invasion was the Gram stain of amniotic fluid (specificity: for Gram stain 98.5%; for white blood cell count 77.9%; for interleukin-6 75%; for glucose 73.5%; p < 0.01 for all); (5) of all amniotic fluid tests, interleukin-6 determination was the only test that had significant cl inical value in the prediction of the amniocentesis-to-delivery interv al and neonatal complications. CONCLUSION: Interleukin-6 concentration s in amniotic fluid are a better predictor of microbial invasion of th e amniotic cavity, amniocentesis-to-delivery interval and neonatal com plications than the amniotic fluid Gram stain, glucose, or white blood cell count in patients with preterm premature rupture of membranes.