Lecithin-sphingomyelin (L/S) ratio - amniotic fluid
Last updated: Thursday, 22, April, 2004
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| Item | Process |
|---|---|
| Specimen | Amniotic fluid. |
| Method | Thin layer chromatography. Some laboratories also measure phosphatidyl glycerol or count lamellar bodies. |
| Reference Interval | L/S ratio >2.0 indicates fetal lung maturity. |
| Application | Assessment of foetal lung maturity. See also Phosphatidyl glycerol - amniotic fluid and Lamellar bodies - amniotic fluid. |
| Interpretation | L/S ratio <2.0 indicates an increased risk of respiratory distress syndrome (RDS) at delivery. L/S ratio <1.5 indicates a very high risk of developing RDS. Babies of diabetic mothers can develop RDS with L/S ratios >2.0. |
| Reference | Spillman T and Cotton DB. Crit Rev Clin Lab Sci 1989; 27: 341-389. |