II. Indications

III. Mechanism

  1. Nitrazine Paper relies on Prussian blue reaction
  2. Requires alkaline paper to cause reaction

IV. Technique

  1. Obtain fluid for exam (usually after Vaginal Pooling)
  2. Place Nitrazine Paper in fluid
    1. Paper turns bright blue in alkaline fluid

V. 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)

VI. Causes: False Positive Nitrazine positive (pH >7)

  1. Blood
  2. Semen
  3. Antiseptic solutions
  4. Urine with increased pH (alkaline urine)
  5. Vaginal infection or Cervicitis (e.g. Bacterial Vaginosis)

VII. Efficacy

  1. Test Sensitivity: 90-97%
  2. Test Specificity: 70% (as low as 16% in some studies)

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