title: Free metanephrine in human amniotic fluid as an index of fetal sympathetic nervous system maturation.
abstract: Free metanephrine, a major metabolite of catecholamines, was measured in the amniotic fluid of 113 pregnant patients at various gestational ages. The results indicate that prior to 30 weeks the levels of free metanephrine are below the level of assay sensitivity. After 30 weeks' gestation there is a positive correlation of free metanephrine concentrations in amniotic fluid with gestational age. In addition there is a further increase in free metanephrine levels in amniotic fluid with labor.
mesh_terms: D000653:Amniotic Fluid / Q000032:analysis*; D004837:Epinephrine / Q000031:analogs & derivatives*; D005260:Female; D005333:Fetus / Q000502:physiology; D005865:Gestational Age; D006801:Humans; D007743:Labor, Obstetric; D008676:Metanephrine / Q000032:analysis*; D011247:Pregnancy; D013564:Sympathetic Nervous System / Q000196:embryology*
chemical_list: D008676:Metanephrine; D004837:Epinephrine