Improved prediction of fetal lung maturity in diabetic pregnancies: A comparison of chromatographic methods

Following planned termination of pregnancy, infants of diabetic mothers have shown a continued vulnerability to the respiratory distress syndrome (RDS), suggesting false positive results on fetal lung maturity testing. We studied the adequacy of the standard one-dimensional chromatographic lecithin/sphingomyelin (L/S) ratio for predicting RDS in 56 diabetic and 50 nondiabetic pregnancies. An exceptionally low incidence of RDS was noted for the study (0.95%) as well as for diabetic pregnancies alone (1.85%). The clinical results were further compared to a new method for determining L/S ratios and identifying other pulmonary phospholipids by two-dimensional chromatography. Values for two-dimensional L/S ratios were significantly lower from 36 through 38weeks’ gestation (P