title: Is the lecithin/sphingomyelin ratio outdated?
mesh_terms: D005260:Female; D006801:Humans; D007226:Infant Mortality; D007231:Infant, Newborn; D010713:Phosphatidylcholines / Q000032:analysis*; D011247:Pregnancy; D013109:Sphingomyelins / Q000032:analysis*
chemical_list: D010713:Phosphatidylcholines; D013109:Sphingomyelins