Test Code LBC Lamellar Body Count, Amniotic Fluid
Reporting Name
Lamellar Body Count, AFUseful For
Predicting fetal lung maturity and assessing the risk of developing neonatal respiratory distress syndrome, when performed during 32 to 39 weeks gestation
Performing Laboratory

Specimen Type
Amniotic FldSpecimen Required
Container/Tube: Amniotic fluid container or plastic vial
Specimen Volume: 2 mL
Collection Instructions:
1. Do not centrifuge
2. Amniotic specimens must be blood and meconium free.
Specimen Minimum Volume
0.75 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Amniotic Fld | Refrigerated (preferred) | 28 days | |
Ambient | 7 days |
Reference Values
Immature: <15,000/mcL
Indeterminate: 15,000-50,000/mcL
Mature: >50,000/mcL
Cutoffs are based on consensus protocol (Neerhof M, Dohnal JC, Ashwood ER, et al: Lamellar body counts: a consensus on protocol. Obstet Gynecol 2001;97:318-320)
Day(s) and Time(s) Performed
Monday through Sunday; Continuously
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
83664
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
LBC | Lamellar Body Count, AF | 19114-8 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
LBCC | Lamellar Body Count | 19114-8 |
LBCI | Interpretation | 59462-2 |
Clinical Information
Fetal lung maturity testing is used to determine the risk for developing respiratory distress syndrome (RDS) in infants born prematurely (32-39 weeks). The risk for developing RDS is inversely related to gestational age and is the most common cause of respiratory failure in neonates. RDS is associated with preterm birth due to insufficient production of pulmonary surfactant. Pulmonary surfactant is synthesized by type II pneumocytes. Surfactant consists of 90% phospholipids (primarily phosphatidylcholine and phosphatidylglycerol) and 10% proteins (surfactant proteins [SP]-A, SP-B, SP-C). Surfactant is packaged into lamellar bodies and is excreted into the alveolar space where it unravels and forms a monolayer on alveolar surfaces. Lamellar bodies can also pass into the amniotic cavity and, hence, are found in amniotic fluid. The surfactant functions to reduce the surface tension in the alveoli, preventing atelectasis. When surfactant is deficient, the small alveoli collapse and the large alveoli become overinflated and stiff, which has been associated with increased risk of developing respiratory distress. The status of fetal lung maturity is reflected in the concentration of surfactant in the form of phospholipids and lamellar bodies present in amniotic fluid. Lamellar bodies are similar in size to platelets and can be quantified on a hematology analyzer utilizing the platelet channel and used to estimate fetal lung maturity.
Reject Due To
Gross hemolysis | Reject |
Other | Centrifuged specimen. Presence of blood or meconium |
NY State Approved
YesMethod Name
Sysmex XN-9000, Platelet Count by Impedance Method