Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (927 page)

   Use

   Predicting FLM and assessing the risk of developing neonatal respiratory distress syndrome, when performed during 32–39 weeks of gestation

   Interpretation

   Increased in mature fetal lungs

   Decreased in immature fetal lungs

   Limitations

   It is as accurate as TDM/FLEXII FPIA method (no longer available) surfactant/albumin ratio.

   LBCs not indicated >39 weeks of gestation.

   Amniotic fluid samples should be free of blood or meconium contamination.

FIBRINOGEN (FACTOR I)
*

   Definition

   Fibrinogen is a glycoprotein synthesized in the liver. It is modified by thrombin to become fibrin, a visible clot. It is also an acute-phase reactant.

   
Normal range:
150–400 mg/dL (most abundant circulating clotting factor).

   Use

   This test detects decreased or abnormal fibrinogen.