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Bilirubin in Amniotic Fluid

Amniotic Fluid Analysis for Hemolytic Disease of the Newborn, Amniotic Fluid Spectural Analysis, Liley Test

Test Codes

MAYO: AFBIL. Order as a Miscellaneous Send Out.

Specimen Collection Criteria

Collect: 3.5 mL amniotic fluid in a sterile collection container. (Minimum: 1.7 mL)

Protect specimen from light after collection. 

Gestational age at time of amniocentesis is required.

Physician Office/Draw Specimen Preparation

Protect specimen from light. Maintain specimen refrigerated (2-8°C or 36-46°F) until transport.

Preparation for Courier Transport

Transport: Light-protected amniotic fluid in a sterile collection container, refrigerated (2-8°C or 36-46°F).

Rejection Criteria

Specimens not protected from light.

Specimens not collected and processed as indicated.

In-Lab Processing

Protect specimen from light. Maintain specimen refrigerated (2-8°C or 36-46°F).

Transport: Light-protected amniotic fluid in a sterile collection container, refrigerated (2-8°C or 36-46°F).

Storage

Specimen Stability for Testing:

Room Temperature (20-26°C or 68-78.8°F): 4 hours
Refrigerated (2-8°C or 36-46°F): 24 hours
Frozen (-20°C/-4°F or below): 70 days

Specimen Storage in Department Prior to Disposal:

Specimen retention time is determined by the policy of the reference laboratory. Contact the Send Outs Laboratory with any questions.

Laboratory

Sent to Mayo Medical.

Performed

Monday – Saturday.
Results available in 2-4 days.

Reference Range

Reference values are dependent on duration of pregnancy.

Test Methodology

Spectrophotometric Scan.

Interpretation

Results are reported as "corrected absorbance at 450 nm" together with the corresponding zone (lower, mid, upper) from the Liley chart. Values falling in the upper zone are usually associated with severly-affected fetuses/neonates, those in the lower zone are usually associated with unaffected or mildly affected fetuses/neonates.

Clinical Utility

Maternal RBC antibodies may cause hemolytic disease in the fetus and neonate. The level of bilirubin in amniotic fluid is proportional to the degree of hemolysis and is therefore used to assess the developing fetus.

CPT Codes

82247
LOINC:  5770-3

Contacts

Last Updated

8/12/2021