[Determination and clinical application of the lecithin/sphingomyelin ratio in amniotic fluid by high performance liquid chromatography].

The lecithin/sphingomyelin (L/S) ratios in standard solution and amniotic fluid of 64 pregnant women were measured by high performance liquid chromatography (HPLC). The procedure is highly accurate, and the correlation coefficient between the HPLC value and standard solution was 0.984. The regression line was: Y = 0.8X + 0.17 (Y: standard solution X: HPLC values). In 64 pregnant women, 41 cases were delivered within 72 hrs of the amniotic fluid collection. The prediction of respiratory distress syndrome (RDS) was performed with variables of the L/S ratio less than 4.20. 8 of 9 babies (88.9% of sensitivity) who developed RDS and 3 of 3 (100% of sensitivity) other types of respiratory failure due to hydrothorax were predicted by this method. In conclusion, this method is simple, rapid and sensitive for the prediction of respiratory distress syndrome and other respiratory failure.