Red blood cell and plasma polyamines in umbilical and maternal blood at delivery were measured using high performance liquid chromatography. The concentration of each polyamine in red blood cells and plasma of umbilical blood was significantly higher than in maternal blood. Spermidine and spermine concentrations in fetal red blood cells decreased markedly with the progress of pregnancy. In addition, younger red blood cells contained more polyamines than older cells. Red blood cell polyamines are closely associated with the cell membrane. Plasma polyamine in umbilical blood reflect active fetal metabolism, whereas red blood cell polyamines mainly reflect alterations in erythropoiesis in bone marrow and may indicate the proliferation of the bone marrow.</p
