FBR Resource Guide

Fetal Blood Contamination, Amniotic Fluid (FBC-R)
Bovine Serum Contamination, Amniotic Fluid (BSA-R)

Prenatal Screening Laboratory

Counterimmunoelectrophoresis and radialimmunodiffusion


Specimen Required:

Amniotic fluid: 1 mL

Include 1 mL whole fluid if visibly bloody

Room temperature or 4°C

Days Test Set Up:

FBC - Monday-Thursday
BSA - Friday.

Analytic Time:

24 hours

Reference Values:

No precipitin band = Normal

CPT Code(s):

86331, 86185

Relevance:

The presence of fetal serum in amniotic fluid can contribute to elevated amniotic fluid alpha-fetoprotein or positive acetylcholinesterase (AChE).

Notes:

The presence of fetal bovine serum albumin (BSA), another cause of false positive AChE results, can be confirmed with this same method.

Reference(s)