Endogenous and recombinant erythropoietin levels decline in human amniotic fluid and fetal plasma in vitro at 37 degrees C.

Abstract

To determine the in vitro stability of endogenous and recombinant erythropoietin (EPO) incubated at 37 degrees C in amniotic fluid (AF) and fetal plasma. Endogenous and recombinant EPO in AF, fetal plasma and phosphate buffer were incubated in vitro for 21 days at 37 degrees C. Serial aliquots were analyzed for EPO and the rates of EPO decline were compared within and between groups. Endogenous and recombinant EPO declined significantly in plasma and AF at 37 degrees C. Endogenous EPO displayed a similar linear rate of decline in AF and plasma, with nearly 70% of the initial hormone concentration remaining at 21 days. Recombinant EPO incubated in buffer did not change. Using the rate of decline in endogenous EPO we observed, EPO levels measured in AF or plasma within 21 days of fetal demise can be extrapolated back to the level likely present at fetal death.