title: Endogenous and recombinant erythropoietin levels decline in human amniotic fluid and fetal plasma in vitro at 37 degrees C.
abstract: OBJECTIVE
  To determine the in vitro stability of endogenous and recombinant erythropoietin (EPO) incubated at 37 degrees C in amniotic fluid (AF) and fetal plasma.
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, IA, USA.
authors.forename: Nicole M
authors.initials: NM
authors.lastname: Schmidt
authors.forename: Robert A
authors.initials: RA
authors.lastname: Schmidt
authors.forename: Kari A
authors.initials: KA
authors.lastname: Teramo
authors.forename: John A
authors.initials: JA
authors.lastname: Widness
mesh_terms: D000653:Amniotic Fluid / Q000737:chemistry*; D004355:Drug Stability; D004921:Erythropoietin / Q000032:analysis*; D005260:Female; D005312:Fetal Blood / Q000737:chemistry*; D005313:Fetal Death / Q000175:diagnosis; D006801:Humans; D011247:Pregnancy; D011863:Radioimmunoassay; D011994:Recombinant Proteins; D013997:Time Factors
chemical_list: D011994:Recombinant Proteins; D004921:Erythropoietin