<prompt> Which one of the following is true of hyaline membrane disease of the newborn -Prematurity provides relative protection of the occurrenceMaternal steroid exposure increase severity of the diseasePhosphatidyl glycerol estimation is a reliable method of diagnosisSurfactant increases the surface tension of a lveoli  <response>: Ans. is c i.e., Phosphatidyl glycerol estimation is a reliable method of diagnosis o In HMD surfactant is reduced and its measurement can be used for diagnosis e.g. in shake test. o Constituent of surfactant are - dipalmitoyl phosphatidylcholine lecithin, phosphatidylglycerol, apoproteins surfactant proteins --- SPA, SPB, SPC, SPD and cholesterol. 