The relationship between human fetal cardiovascular hemodynamics and serum erythropoietin levels in growth-restricted fetuses

Objective: We hypothesized that in growth restricted fetuses, erythropoietin (EPO) secretion is increased in proportion to the severity of cardiovascular compromise. Study Design: Thirty-eight growth restricted fetuses underwent Doppler ultrasonography of cardiovascular hemodynamics. An umbilical artery (UA) blood sample was taken at delivery for EPO analysis. Group 1 fetuses (n=9) had normal UA and ductus venosus (DV) velocimetries. Group 2 fetuses (n=18) showed an abnormal UA and a normal DV velocimetry. Group 3 fetuses (n=11) had abnormal UA and DV velocimetries. Normal EPO values were determined in 19 uncomplicated pregnancies (control group). Results: In group 3, EPO levels were higher (P<.05) than in groups 1 and 2. All fetuses in group 3 had EPO concentrations above the 90^th percentile EPO value in the control group. The corresponding incidences were 44% and 50% in groups 1 and 2. Fetuses with retrograde aortic isthmus net blood flow had greater (P<.001) EPO levels than fetuses with antegrade net blood flow. Descending aorta, UA, DV and left hepatic vein pulsatility index values correlated significantly with EPO concentrations. Conclusion: In fetal growth restriction, serum EPO concentration is increased in proportion to the severity of fetal cardiovascular compromise. Furthermore, in fetuses with retrograde aortic isthmus net blood flow, EPO levels are increased.