Comparison of gram stain, leukocyte esterase activity, and amniotic fluid glucose concentration in predicting amniotic fluid culture results in preterm premature rupture of membranes.

OBJECTIVE

The purpose of this study was to prospectively compare three rapid and inexpensive tests that have been proposed as predictors of amniotic fluid culture results in preterm premature rupture of membranes.

STUDY DESIGN

Amniocentesis was performed on 117 patients < or = 34 weeks' gestational age with premature rupture of membranes and no clinical evidence of infection. Amniotic fluid was sent for Gram stain and aerobic, anaerobic, and Mycoplasma cultures. Leukocyte esterase activity and glucose concentration were also determined on the amniotic fluid.

RESULTS

Amniotic fluid cultures were positive in 56 patients (47.8%). Leukocyte esterase activity of 1+ or 2+ and an amniotic fluid glucose concentration < or = 16 mg/dl were significantly more sensitive (p < 0.005) than Gram stain in detecting positive amniotic fluid cultures (73%, 68%, and 41%, respectively).

CONCLUSIONS

Although each of these rapid tests is useful in assessing for subclinical intraamniotic infection, none of them have sufficient accuracy to make clinical decisions solely on the basis of their results.