Umbilical plasma erythropoietin correlations with blood gases and gestational age in appropriately grown infants.

Erythropoietin (EPO) levels were measured using an ELISA method in umbilical cord plasma from 68 appropriately grown neonates at 27 to 43 weeks of gestation (EGA). A consistent but small (5%) difference was found between the EPO levels in the umbilical artery (Ua), 21.0 +/- 2.5 mlU/mL (mean +/- SEM), and umbilical vein (Uv), 22.0 +/- 2.7 mlU/mL (p < 0.02, n = 30). Significant inverse correlations were found between Ua EPO levels and pO2 (r = -0.44, p < 0.002), pH (r = -0.68, p < 0.0001), as well as base deficit (r = -0.56, p < 0.0001). A significant correlation was found between EGA and Ua EPO from 27 to 43 weeks of gestation (r = 0.45, p < 0.001, n = 68). One and 5 minute Apgar scores did not correlate with EPO. These findings indicate that EPO correlates strongly with cord gas parameters and thus may serve as a clinically useful marker for both subacute fetal distress and chronic uteroplacental insufficiency.