[Lecithin in the amniotic fluid in the determination of fetal lung maturity].

A prospective study involved 90 patients divided into groups of high risk and risk pregnancies, which matched in age, parity and gestational age. Two methods for the amniotic fluid phospholipid analysis were compared. The value of lecithin was measured by the two phase UV enzyme method and the lecithin/sphingomyelin (L/S) ratio was determined by Gluck's method. The correlation of lecithin and the L/S ratio with gestational age did not prove statistically significant. No correlation was found between the lecithin concentration and L/S ratio on the one hand and the occurrence of the respiratory distress syndrome on the other. The increase of RDS in high risk pregnancies was not statistically significant. The lecithin concentration determination appeared to be a more specific method (37%) than the L/S ratio (19%), and the predictive value of the negative test also proved to be higher (94%) in relation to the L/S ratio (89%).