Abstract

AbstractOne hundred three amniotic fluid samples from 72 patients were examined for fetal maturity by a modified technic for lecithin/sphingomyelin (L/S) ratio, Nile blue and creatinine tests, and some also by osmolality. Our modification of the L/S technic gives nearly equal staining intensities for equimolar amounts of lecithin and sphingomyelin, and a ratio of 5 or greater indicates maturity. Criteria for maturity by the Nile blue test are 20% or more fatty cells or presence of large free fat globules or both. Follow-up of the neonatal course was obtained in 71 cases. The most reliable predictors of fetal pulmonary maturity, based on absence of neonatal respiratory distress syndrome (RDS), were the Nile blue and L/S tests. However, neither was infallible. RDS occurred in one infant after a positive Nile blue test and in two infants after L/S of 5 or more.