Test ID FLP Fetal Lung Profile, Amniotic Fluid
Useful For
Determining the ability of fetal lungs to produce sufficient quantities of pulmonary surfactant
Assessing the risk of developing neonatal respiratory distress in fetuses delivered less than 39 weeks gestational age
Special Instructions
Method Name
Thin-Layer Chromatography (TLC) with Quantitation by
Densitometry
Includes lecithin/sphingomyelin (L/S) ratio, and
phosphatidylglycerol (PG), semiquantitative on amniotic fluid.
Reporting Name
Fetal Lung Profile, AFSpecimen Type
Amniotic FldContainer/Tube: Amniotic fluid container
Specimen Volume: 10 mL
Collection Instructions:
1. Centrifuge at 1,000 rpm or 200 x G for 10 minutes, separate supernatant and send both supernatant and sediment in separate plastic vials.
2. Label specimens sediment and supernatant.
Additional Information: Include estimate of duration of pregnancy (in weeks).
Forms: New York Clients-Informed consent is required. Please document on the request form or electronic order that a copy is on file. An Informed Consent for Genetic Testing (T576) is available in Special Instructions.
Specimen Minimum Volume
3 mL
Specimen Stability Information
Specimen Type | Temperature | Time |
---|---|---|
Amniotic Fld | Frozen (preferred) | 14 days |
Ambient | 72 hours | |
Refrigerated | 72 hours |
Clinical Information
Respiratory distress syndrome is a common complication of prematurity occurring in infants whose lungs lack the surfactant necessary for healthy lung inflation and air exchange. Surfactant is not produced in sufficient quantity until relatively late in gestation. It is primarily made up of phospholipids such as lecithin and phosphatidylglycerol, which can be detected in amniotic fluid and used as markers for fetal lung maturity. Both the lecithin/sphingomyelin (L/S) ratio and phosphatidylglycerol (PG) concentration increase with gestational age and correlate with lung maturity. Testing both the L/S ratio and the presence or absence of PG provides a better assessment of neonatal risk than the use of either test alone.
Reference Values
Lecithin/ Sphingomyelin Ratio |
Phosphatidylglycerol |
Interpretation |
<2.5 |
Absent |
Immature |
≥2.5 |
Absent |
Indeterminate |
<2.5 |
Trace |
Indeterminate |
≥2.5 |
Trace |
Mature |
Any ratio |
Present |
Mature |
All results will be called back. |
Cautions
No significant cautionary statements
Day(s) Performed
Testing set-up until 2 pm Monday through Saturday, and 11 am Sunday
Samples received after these times will be run the next day.
Report Available
1 dayPerforming Laboratory

Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.CPT Code Information
83661-Fetal lung maturity assessment; L/S ratio
84081-PG