Lecithin‐Bound Palmitic Acid and Lecithin/Sphingomyelin‐Ratio of Amniotic Fluid in Relation to Fetal Maturity

Abstract

The proportion of lecithin-bound palmitic acid and the lecithin/sphingomyelin-ratio were determined in human amniotic fluid during the third trimester. All the cases studied terminated in the birth of healthy children. The proportion of palmitic acid in the lecithins increased with advancing gestational age until 39-40 weeks, when it flattened off and then tended to decline slightly. The lecithin/sphingomyelin-ratio also increased with advancing gestational age, but within each week there was a considerable variance. Complicated pregnancies did not differ from normal ones. The results indicate that determination of the proportion of lecithinbound palmitic acid in amniotic fluid might be an additional variable of clinical value in estimating foetal maturity.