although there were no differences between umbilical arterial and umbilical venous plasma erythropoietin levels ( 21.3 +/- 9.3 versus 19.0 +/- 7.8 mu/ml ) , mixed cord serum was inexplicably higher ( 24.4 +/- 9.5 mu/ml , p less than 0.01 ) .
C0032105
plasma
C0229671
serum