title: Catalase activity as a predictor of amniotic fluid culture results in preterm labor or premature rupture of membranes.
abstract: OBJECTIVE
  To evaluate catalase activity as a rapid predictor of microbial invasion of amniotic fluid (AF).
  
  
  METHODS
  The study population consisted of 74 patients before 36 weeks' gestation with preterm labor or premature rupture of membranes (PROM). Subjects were excluded if there was evidence of clinical chorioamnionitis or fetal distress at admission. Amniocentesis was done within 24 hours of admission, and the AF was cultured for aerobic and anaerobic bacteria and for Mycoplasma species. All AF samples were Gram stained, and slides were examined by microbiology technologists. Amniotic fluid catalase activity was measured immediately after amniocentesis using a commercially available kit. The sensitivity of the Gram stain and catalase activity were compared using McNemar exact test.
  
  
  RESULTS
  Amniotic fluid cultures were positive in 12 of 37 (32%) patients presenting with preterm labor and in 21 of 37 (56%) patients with PROM. Catalase activity was significantly more sensitive than Gram stain in detecting positive AF cultures in cases of PROM (P < .001) and preterm labor (P < .04).
  
  
  CONCLUSIONS
  Catalase activity is a simple, rapid test that is useful in identifying subclinical intra-amniotic infection in patients with preterm labor or PROM.
authors.affiliation: Department of Obstetrics and Gynecology, University of Illinois, Chicago, USA.
authors.forename: G E
authors.initials: GE
authors.lastname: Font
authors.forename: D W
authors.initials: DW
authors.lastname: Gauthier
authors.forename: W J
authors.initials: WJ
authors.lastname: Meyer
authors.forename: T D
authors.initials: TD
authors.lastname: Myles
authors.forename: W
authors.initials: W
authors.lastname: Janda
authors.forename: A
authors.initials: A
authors.lastname: Bieniarz
mesh_terms: D000653:Amniotic Fluid / Q000201:enzymology* / Q000382:microbiology; D002374:Catalase / Q000378:metabolism*; D005260:Female; D005322:Premature Rupture of Fetal Membranes / Q000382:microbiology*; D005865:Gestational Age; D006801:Humans; D007752:Obstetric Labor, Premature / Q000382:microbiology*; D011237:Predictive Value of Tests; D011247:Pregnancy; D012680:Sensitivity and Specificity; D013194:Staining and Labeling; D016990:Ureaplasma urealyticum / Q000201:enzymology
chemical_list: D002374:Catalase