title: The presence of vaginal Lactobacillus species does not contribute to a measureable difference in amniotic fluid lactate levels collected from the vaginal tract of laboring women.
abstract: BACKGROUND
  Amniotic fluid lactate research is based on the hypothesis that a relationship exists between fatigued uterine muscles and raised concentrations of the metabolite lactate, which is excreted into the amniotic fluid during labor. To assess potentially confounding effects of lactate-producing organisms on amniotic fluid lactate measurements, we aimed to determine if the presence of vaginal Lactobacillus species was associated with elevated levels of amniotic fluid lactate, measured from the vaginal tract of women in labor.
  
  
  METHODS
  Results from this study contribute to a large prospective longitudinal study of amniotic fluid lactate at a teaching hospital in Sydney, Australia. Amniotic fluid lactate measurement was assessed at the time of routine vaginal examination, after membranes had ruptured, using a hand-held lactate meter StatStripXPress (Nova Biomedical). Vaginal swab samples were collected at the time of the first amniotic fluid lactate measurement and stored for later detection and quantification of Lactobacillus species using a TaqMan real-time PCR assay. Swab sample and amniotic fluid lactate results were paired and analyzed.
  
  
  RESULTS
  The PCR assay detected Lactobacillus species in 48 of 388 (12%) vaginal swab specimens (8% positive, 4% low positive) collected from women in labor after membranes had ruptured. There was no significant difference in median and mean (respectively) amniotic fluid lactate levels with (8.35 mmol/L; 8.95 mmol/L) or without (8.5 mmol/L; 9.08 mmol/L) Lactobacillus species detected.
  
  
  CONCLUSIONS
  There was no association between the presence or level of vaginal Lactobacillus species and the measurement of amniotic fluid lactate collected from the vaginal tract of women during labor.
authors.affiliation: Midwifery and Women's Health Research Unit, Royal Hospital for Women, Randwick, University of Sydney, Sydney, NSW, Australia.|Virology Research, Serology and Virology Division, Department of Microbiology, SEALS, Prince of Wales Hospital, Randwick, NSW, Australia.
authors.forename: Beverley
authors.initials: B
authors.lastname: Hall
authors.affiliation: Virology Research, Serology and Virology Division, Department of Microbiology, SEALS, Prince of Wales Hospital, Randwick, NSW, Australia.
authors.forename: Diana
authors.initials: D
authors.lastname: Wong
authors.affiliation: Midwifery and Women's Health Research Unit, Royal Hospital for Women, Randwick, University of Sydney, Sydney, NSW, Australia.
authors.forename: Clare
authors.initials: C
authors.lastname: Healy
authors.affiliation: Center for Newborn Care, Westmead Hospital, Westmead, NSW, Australia.|Department of Paediatrics and Child Health, University of Sydney, Camperdown, NSW, Australia.
authors.forename: Mark B
authors.initials: MB
authors.lastname: Tracy
authors.affiliation: Midwifery and Women's Health Research Unit, Royal Hospital for Women, Randwick, University of Sydney, Sydney, NSW, Australia.
authors.forename: Sally K
authors.initials: SK
authors.lastname: Tracy
authors.affiliation: Virology Research, Serology and Virology Division, Department of Microbiology, SEALS, Prince of Wales Hospital, Randwick, NSW, Australia.|School of Medical Sciences, Faculty of Medicine and School of Biotechnology and Biomolecular Sciences, University of New South Wales, Kensington, NSW, Australia.
authors.forename: William D
authors.initials: WD
authors.lastname: Rawlinson
mesh_terms: D000293:Adolescent; D000328:Adult; D000653:Amniotic Fluid / Q000378:metabolism*; D005260:Female; D006785:Hospitals, University; D006801:Humans; D007743:Labor, Obstetric / Q000378:metabolism*; D019344:Lactic Acid / Q000378:metabolism*; D007778:Lactobacillus / Q000302:isolation & purification*; D008137:Longitudinal Studies; D009517:New South Wales; D011237:Predictive Value of Tests; D011247:Pregnancy; D011446:Prospective Studies; D014621:Vagina / Q000382:microbiology*; D055815:Young Adult
chemical_list: D019344:Lactic Acid
keywords: 
  Lactobacillus
  ; Amniotic fluid lactate; dystocia; labor; lactate