Abstract:

Objective To establish a method based on ultra-performance liquid chromatography-tandem mass spectrometry（UPLC-MS/MS） to measure the ratio of lecithin/sphingomyelin（L/S） in amniotic fluid to accurately and efficiently predict fetal lung maturity. Methods According to the Apgar scoring standard for newborns,23 amniotic fluid specimens obtained at 32-39 gestational weeks were classified into 3 fetal lung immature cases and 20 fetal lung mature cases. Totally,7 amniotic fluid specimens obtained at 18 gestational week were used as baseline controls. UPLC-MS/MS for determining the ratio of L/S in amniotic fluid was established. Lamellar body （LB） was determined by lamellar body count （LBC） method. The roles of the 2 methods for predicting fetal lung maturity were evaluated. Results The UPLC-MS/MS for the determination of L/S had good precision. Both ion peak intensity and retention time were within the determinable range,and principal component analysis （PCA） showed good clustering of 6 quality control samples. When L/S=10 was used as the cut-off value to discriminate maturity and immaturity,the sensitivity and specificity reached 100%. When LB=50×10⁹ /L was used as the cut-off value,2 cases of positive specimens and 1 case of negative specimen were incorrectly identified,with a sensitivity of 80% and a specificity of 95%. Conclusions The measurement of L/S in amniotic fluid by UPLC-MS/MS is reliable and can predict fetal lung maturity accurately and efficiently.

Key words: Lecithin/Sphingomyelin ratio, Ultra-performance liquid chromatography-tandem mass spectrometry, Fetal lung maturity