[Development and comparison of lecithin/sphingomyelin and palmitic acid/stearic acid ratios in amniotic fluid]

Fetal lung maturity has been studied both by silica gel chromatography of phospholipids and gas liquid chromatography of fatty acids. Lecithin/sphingomyelin (L/S) ratios and palmitic/stearic (P/S) ratios were compared. A good correlation was obtained. However, when the L/S ratio has an intermediate value (1.5 less than or equal to L/S less than 2) making it difficult to judge the fetal lung maturity, the P/S ratio expresses the lung maturity more accurately.