title: Letter: Amniotic fluid: visual assessment of fetal maturity.
mesh_terms: D000653:Amniotic Fluid / Q000032:analysis; D005260:Female; D005333:Fetus / Q000502:physiology*; D006801:Humans; D010713:Phosphatidylcholines / Q000032:analysis; D011247:Pregnancy; D011296:Prenatal Diagnosis; D013048:Specimen Handling; D013109:Sphingomyelins / Q000032:analysis
chemical_list: D010713:Phosphatidylcholines; D013109:Sphingomyelins