<prompt> A 28 weeks pregnant multigravida with preeclampsia presented with fulminant signs. Urgent C-section was planned. Best method for the diagnosis of lung maturity is:LS ratio in amniotic fluidPhosphtidyl glycerol estimation in amniotic fluidBilirubin in amniotic fluidAmniotic fluid creatinine  <response>: Phosphatidylglycerol PG is a minor constituent of surfactant. It begins to increase appreciably in amniotic fluid several weeks after the rise in lecithin. Its presence is more indicative of fetal lung maturity because PG enhances the spread of phospholipids on the alveoli. Ref: Mehta S.H., Sokol R.J. 2007. Chapter 13. Methods of Assessment for Pregnancy at Risk. In A.H. DeCherney, L. Nathan Eds, CURRENT Diagnosis Treatment Obstetrics Gynecology, 10e. 