Also found in: Dictionary, Thesaurus, Financial, Encyclopedia.
lecithin/sphingomyelin ratio(L-S ratio)
the ratio of lecithin to sphingomyelin in amniotic fluid, the determination of which is helpful in establishing the maturity of the fetus and its susceptibility to hyaline membrane disease after birth.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.
lec·i·thin/sphin·go·my·e·lin ra·ti·o (L:S ra·ti·o),
a ratio used to determine fetal pulmonary maturity, found by testing the amniotic fluid; when the lungs are mature, lecithin exceeds sphingomyelin by 2 to 1.
Farlex Partner Medical Dictionary © Farlex 2012
lecithin/sphingomyelin ratioL/S ratio Obstetrics The ratio of lecithin–phosphatidyl choline to sphingomyelin, a 'bench' parameter used to determine lung maturity and predict an infant's ability to survive without developing respiratory distress. See Biophysical profile, Lung profile, Respiratory distress syndrome.
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.