Fetal erythropoietin levels in growth-restricted and appropriately grown neonates with and without abnormal fetal heart rate tracings: A comparison with cord blood gases and Apgar scores

OBJECTIVE: To determine if umbilical cord plasma erythropoietin (EPO) levels in combination with cord blood gases and Apgar scores can distinguish between subacute and chronic uteroplacental insufficiency. METHODS: A total of 184 neonates delivered between 1993 and 1997 at Tampa General Hospital were studied. Cord plasma EPO levels, cord blood gases, and Apgar scores were determined prosnectively and compared in four subgroups that were defined based on the presence or absence of fetal growth restriction (FGR; chronic fetal hypoxia), abnormal fetal heart rate tracings during labor (FHR; subacute/acute fetal hypoxia), or both. RESULTS: Both growth-restricted and appropriately grown newborns with abnormal intrapartum FHR tracing had elevated umbilical cord plasma EPO (183.5 and 135.2 mIU/ml, respectively; normal = 20.7 mIU/ml) and base deficit, whereas pH, Po2, and 1-minute and 5-minute Apgar scores were significantly lower, compared with appropriately grown newborns with a normal intrapartum course. Among newborns with normal heart rate tracings and FGR, the mean plasma EPO levels were elevated (89.5 mIU/ml), whereas the other parameters were not different from normal. CONCLUSION: Our findings suggest that, although cord blood gases and Apgar scores may reflect subacute and acute events, they are not good predictors of chronic uteroplacental insufficiency. The supplemental use of umbilical cord plasma EPO levels may improve our ability to identify chronic uteroplacental insufficiency.