Lab

Vaginal Fluid pH

search

Vaginal Fluid pH, Nitrazine Paper, Nitrazine

  • See Also
  1. Premature Rupture of Membranes
  2. Ferning of Vaginal Fluid
  3. Vaginal Pooling
  4. AmniSure ROM Test (PAMG-1 Protein Marker Test)
  • Indications
  1. Evaluation for Premature Rupture of Membranes
  • Mechanism
  1. Nitrazine Paper relies on Prussian blue reaction
  2. Requires alkaline paper to cause reaction
  • Technique
  1. Obtain fluid for exam (usually after Vaginal Pooling)
  2. Place Nitrazine Paper in fluid
    1. Paper turns bright blue in alkaline fluid
  • Interpretation
  • Nitrazine Paper
  1. Normal Vaginal pH 4.5-6.0
    1. Paper does not change color
  2. Ruptured Vaginal pH 7.1-7.3
    1. Suggests PROM (paper blue)
  1. Blood
  2. Semen
  3. Antiseptic solutions
  4. Urine with increased pH (alkaline urine)
  5. Vaginal infection or Cervicitis (e.g. Bacterial Vaginosis)
  • Efficacy
  1. Test Sensitivity: 90-97%
  2. Test Specificity: 70% (as low as 16% in some studies)
  • .
  • References
  1. Bennett (1993) Am J Perinatol 10(2):101-4 [PubMed]