title: L/S ratios and RDS.
mesh_terms: D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008722:Methods; D010713:Phosphatidylcholines / Q000032:analysis*; D011247:Pregnancy; D012127:Respiratory Distress Syndrome, Newborn / Q000175:diagnosis*; D013109:Sphingomyelins / Q000032:analysis*
chemical_list: D010713:Phosphatidylcholines; D013109:Sphingomyelins