Biochemical monitoring of fetal distress with serum-immunoreactive erythropoietin.

The ability of parameters like umbilical arterial pH and Apgar score to predict and/or to reflect fetal distress are limited. It is known that erythropoietin (EPO) increases when partial pressure of oxygen is insufficient for metabolic demand. Therefore we studied the levels of EPO in the cord blood of stressed neonates (n = 75). In addition, reference values for EPO were established in a group of healthy term infants (n = 54) (mean +/- SD: 20.02 +/- [mU/ml]) and in premature infants (n = 77) according to gestational age. A significant increase in EPO concentrations was found in the stressed group: 153.4 +/- 418.8 [mU/ml], p < 0.003 (n = 27) in acute stress; and 102.6 +/- 127.1 [mU/ml], p < 0.002 (n = 48) in chronic stress. However parameters like hemoglobin, hematocrit, umbilical arterial pH and Apgar-score did not correlate with EPO values. A sensitivity of 59% and a specificity of 92% was calculated. We conclude that serum EPO concentrations are capable of detecting acute and chronic stress and could be useful as a screening method. In part EPO concentrations also allow us to grade stress in pregnancies that are complicated by diseases like preeclampsia.