Test Code FERN Fern test; Amniotic Fluid Crystallization test
Additional Codes
ALAB: FERN
Powerchart: Fern Test
Test Method
Microscopy
Specimen Requirement
A vaginal swab obtained from the posterior vaginal pool.
Additional Specimen Collection Information
Collection Instructions:
- A vaginal swab obtained from the posterior vaginal pool. As when handling any bodily fluid, Universal Precautions must be observed.
- Position the patient in the dorsal lithotomy position.
- Avoiding the use of lubricant or antiseptic, place a sterile speculum into the vaginal vault.
- Using a sterile cotton swab, obtain a sample of the vaginal secretion from the posterior vaginal pool.
- Smear a thin layer of the fluid obtained on the center portion of a clean glass microscope slide.
- Allow the slide to air dry for at least 5 – 7 minutes. Do not wave or blow on the slide and do not apply heat to assist in drying.
Performance
Testing is performed Monday through Sunday.
Routine: Typically completed within 4 hours after the specimen arrives at the testing site.
STAT: Typically completed within 1 hour after the specimen arrives at the testing site.
Reference Value
The test is run based entirely on clinical presentation and must be interpreted in light of the clinical situation.
Useful For
Used for the qualitative determination of the presence of amniotic fluid in a vaginal pool specimen.