Lab

Vaginal Fluid Ferning

search

Vaginal Fluid Ferning, Ferning

  • See Also
  1. Premature Rupture of Membranes
  2. Vaginal Fluid pH (Nitrazine)
  3. Vaginal Pooling
  4. AmniSure ROM Test (PAMG-1 Protein Marker Test)
  • Indications
  1. Evaluation for Premature Rupture of Membranes
  • Technique
  1. Obtain fluid for exam (usually after Vaginal Pooling)
  2. Place sample on glass slide
  3. Allow sample to air dry for 10 minutes
  • Interpretation
  1. Slide shows Ferning pattern under microscopy
  • Efficacy
  1. Test Sensitivity: 98% when in labor (51% if not in labor)
  2. Test Specificity: 88% when in labor (70% if not in labor)
  • Differential Diagnosis
  1. False Positive for Ferning
    1. Cervical Mucus
    2. Semen
  2. False Negative for Ferning
    1. Slide not allowed to dry 10 minutes
    2. Swab dry
    3. Contamination with blood
  • References
  1. Bennett (1993) Am J Perinatol 10(2):101-4 [PubMed]