<prompt> Fetal lung maturity is signified by all except -L-S 237 weeks gestationLevel of phosphatidyl cholineNon reactive NST  <response>: Ans. is d i.e., Non reactive NST Assessment of fetal lung maturityEstimation of pulmonary1 surfactant by lecithinsphingomyelin LS ratio. A ratio of 2 indicates fetal lung maturity, which is normally attained at the age of 35 weeks.Shake test or Bubble test Clements is useful bed side test. If positive indicates fetal lung maturity.Foam stability1 index FSI should be 47.Presence of phosphatidyl PG in amniotic fluid is tested by thin layer chromatography. If present indicates fetal lung maturitySaturated phosphatidyl choline level equivalent or more than 500 ngml indicates fetal lung maturityFluorescence polarisation presence of 55 mg of surfactant per gram of albumin indicates fetal lung maturityAmniotic fluid optical density at 650 mp greater than 0.15 indicates fetal lung maturityLamellar body count of 30,000ml indicates fetal lung maturityOrange colour cells 50 indicates fetal lung maturityAmniotic fluid turbidity 