A study of the lecithin/sphingomyelin ratio of amniotic fluid.
1. There is a significant correlation between lecithin/sphingomyelin (L/S) ratios based on densitometry (L/S)D and L/S ratios based on phosphorus determinations ((L/S)P). 2. The fetal lung is mature when the (L/S)D, determined according to Verhoeven, A.G.J. and Merkus, H.M.W.M. (1974) Clin. Chim. Acta 53, 229--232, is 1.2. This value is equivalent to an (L/S)P of 1.8. 3. The acetone precipitation procedure, introduced by Gluck, L., Kulovich, M.V., Borer, R.C. and Keidel, W.N. (1974) Am. J. Obstet. Gynecol. 120, 142--155, is a necessary step for isolating surface-active lecithin. 4. Standardization of the (L/S)D test is feasible and should permit different laboratories to use the same transition point.
D000653:Amniotic Fluid / Q000032:analysis*; D000818:Animals; D001923:Brain Chemistry; D002417:Cattle; D004530:Egg Yolk; D005227:Fatty Acids / Q000032:analysis; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008168:Lung / Q000196:embryology; D010713:Phosphatidylcholines / Q000032:analysis*; D011247:Pregnancy; D011296:Prenatal Diagnosis; D012127:Respiratory Distress Syndrome, Newborn / Q000175:diagnosis; D013109:Sphingomyelins / Q000032:analysis*; D013500:Surface Tension
D005227:Fatty Acids; D010713:Phosphatidylcholines; D013109:Sphingomyelins