Step 1 Study Topics: Fetal Lung Maturity


This page is dedicated to compiling Step 1 study notes for the topic of fetal lung maturity. This page is likely disorganized as it was made in haste.


Some important points to remember: 

  • Phospholipids, such as dipalmitoyl phosphatidylcholine, are a major component of pulmonary surfactant. 
  • The level of phosphatidylcholine (also called lecithin) is measured in a amniotic fluid in order to gauge fetal lung maturity. 
  • When the lecithin to sphingomyelin (L/S) ratio is greater then/equal to 2 in the amniotic fluid, the lung is considered mature 
  • In cases of preterm labor, the L/S ratio is measured order to determine whether or not to give the mother corticosteroids to induce fetal surfactant production. 


Page Updated: 04.07.2017