Figure 1.

Proposed physiological and pathophysiological mechanistic framework of erythropoietin (EPO) production and actions during fetal anemia and during acute and chronic hypoxia. Illustrated are EPO’s effects in the maternal, fetal, and neonatal compartments based on referenced supporting evidence from both basic research and clinical/epidemiologic studies. Unknown or poorly understood mechanisms are indicated in italics with question marks within ovals with grey background and question marks included between the ovals and rectangles indicating uncertain relationships. The protective effect of breast milk EPO on the neonatal intestine for avoiding necrotizing enterocolitis (NEC) is also indicated. The maternal, fetal and neonatal compartments are separated by the lines between. The two bold, vertical short lines between the maternal and fetal compartments depicts the placenta.