title: Letter: Amniotic fluid or maternal urine?
mesh_terms: D000649:Amniocentesis; D000653:Amniotic Fluid / Q000032:analysis*; D005260:Female; D006801:Humans; D011188:Potassium / Q000032:analysis / Q000652:urine*; D011247:Pregnancy; D014508:Urea / Q000032:analysis / Q000652:urine*
chemical_list: D014508:Urea; D011188:Potassium