Fetal Lung Profile, Amniotic Fluid

CPT CODE:

USEFUL FOR:

Determining the ability of fetal lungs to produce sufficient quantities of pulmonary surfactant
Predicting the likelihood of the development of respiratory distress syndrome if the fetus were delivered

SPECIMEN REQUIRED:

10 mL of amniotic fluid. Centrifuge at 1,000 rpm or 200 x G for 10 minutes, separate supernatant, and send both supernatant and sedimentfrozen in separate plastic vials. Do not send specimenscontaminated with blood.Note:     1. Include estimate of duration of pregnancy (in weeks)                   on request form.                  2. Label specimens appropriately (sediment and supernatant).

TRANSPORT TEMPERATURE:

Frozen\Refrig NO\Ambient NO

CLINICAL INFORMATION:

The phospholipid content of the amniotic fluid reflects the degree of development of the fetal lung and the degree of risk for neonatalrespiratory distress if the fetus were to be delivered.
Testing both the lecithin/sphingomyelin (L/S) ratio and thepresence or absence of phosphatidylglycerol (PG) provides a betterassessment of neonatal risk than the use of either test alone.

CLINICAL INTERPRETATION:

L/S ratio <2.5 and PG absent:  ImmatureL/S ratio > or =  2.5 and PG absent:  IndeterminateL/S ratio <2.5 and PG  trace:  IndeterminateL/S ratio > or =  2.5 and PG trace:  Mature PG present:  Mature

REFERENCE VALUES:

Lecithin

Sphingomyelin   Phosphatidyl-     Interpretation

Ratio                   Glycerol 

<2.5                              Absent                        Immature

> or =2.5                      Absent                        Indeterminate

<2.5                              Trace                          Indeterminate

> or =2.5                      Trace                          Mature

Any ratio                     Present                       Mature

All results will be called back.