title: Effect of maternal exercise and fetoplacental growth rate on serum erythropoietin concentrations.
abstract: OBJECTIVE
  This study was undertaken to test the null hypotheses that neither weight-bearing exercise nor fetoplacental growth has a short- or long-term effect on the maternal serum erythropoietin level.
  
  
  METHODS
  Serial blood samples were obtained before and after exercise from seven women who exercised regularly and seven physically active controls before pregnancy and at 8, 16, 24, 32, and 38 weeks' gestation. Fetoplacental growth was assessed both in midpregnancy (ultrasound) and at birth (morphometry).
  
  
  RESULTS
  Maternal serum erythropoietin levels rose with advancing gestation in both groups. Individual patterns, however, were quite variable and not related to differences in fetoplacental growth. There were no significant between-group differences at any time point, but levels rose after exercise in mid and late pregnancy.
  
  
  CONCLUSIONS
  The highly variable, pregnancy-associated changes in maternal serum erythropoietin were unrelated to variability in fetoplacental growth or maternal hematocrit. Absolute levels of erythropoietin are not influenced by regular exercise before or during pregnancy, but small acute elevations are seen after exercise in mid and late pregnancy.
authors.affiliation: Department of Reproductive Biology, Schwartz Center for Metabolism and Nutrition, Case Western Reserve University at MetroHealth Medical Center, Cleveland, OH 44109, USA. jfclapp@metrohealth.org
authors.forename: James F
authors.initials: JF
authors.lastname: Clapp
authors.forename: Kathleen D
authors.initials: KD
authors.lastname: Little
authors.forename: John A
authors.initials: JA
authors.lastname: Widness
mesh_terms: D000328:Adult; D005314:Embryonic and Fetal Development; D004921:Erythropoietin / Q000097:blood*; D015444:Exercise; D005260:Female; D006801:Humans; D009929:Organ Size; D009994:Osmolar Concentration; D010920:Placenta / Q000033:anatomy & histology; D010929:Placentation; D011247:Pregnancy / Q000502:physiology*; D013997:Time Factors
chemical_list: D004921:Erythropoietin