Leukocyte Esterase Activity as a Predictor of Amniotic Fluid Cultures in Preterm Labor

Abstract

Leukocyte esterase activity has been utilized as a rapid screen for urinary tract infection. The purpose of this study was to evaluate leukocyte esterase activity as a rapid predictor of amniotic fluid culture results in patients with preterm labor. Amniocentesis was performed on 121 patients ≤34 weeks estimated gestation age with preterm labor and no clinical evidence of infection. Gram stain as well as aerobic, anaerobic, and Mycoplasma cultures were performed on the amniotic fluid. Leukocyte esterase activity was determined immediately following amniocentesis with the use of a commercially available test strip. Amniotic fluid cultures were positive in 19 subjects (16%). Leukocyte esterase was significantly more sensitive than Gram stain in detecting positive amniotic fluid culture results (79% vs. 42%, respectively; P < 0.02). Tocolysis was either unsuccessful or discontinued due to a positive Gram stain significantly more often when leukocyte esterase activity was present. Leukocyte esterase activity is a rapid and simple bedside test that is useful in assessing for subclinical intraamniotic infection in preterm labor.

Key Words:

• Leukocyte esterase
• Preterm labor
• Intraamniotic infection