title: Noninvasive assessment of glucose and pyruvate uptake by human embryos after intracytoplasmic sperm injection and during the formation of pronuclei.
abstract: OBJECTIVE
  To improve in vitro culture conditions and human embryo selection before transfer after IVF with intracytoplasmic sperm injection (ICSI).
  
  
  METHODS
  A controlled, randomized, prospective study.
  
  
  METHODS
  University hospital-based IVF-ET program.
  
  
  METHODS
  Couples undergoing ICSI.
  
  
  METHODS
  Culture of human embryos in the presence of 1 mM or 5.56 mM glucose and metabolic measurements with the use of noninvasive microfluorescence assays immediately after ICSI to the time of transfer.
  
  
  METHODS
  Embryo development, implantation rate, and glucose and pyruvate uptake.
  
  
  RESULTS
  Fertilization rates, early embryo development, and implantation rates were not significantly different between 1 mM and 5.56 mM glucose. Pyruvate uptake was significantly higher during the formation of the pronuclei, at 15 +/- 0.7 and 11.4 +/- 1.3 pmol/embryo/h for fertilized and unfertilized oocytes, respectively. Pyruvate uptake did not correlate with cleavage stage or embryo morphology. However, during the second day of incubation, pyruvate uptake was significantly higher for the untransferred embryos of pregnant women compared with nonpregnant women, at 17.9 +/- 1.5 and 10.8 +/- 1.0 pmol/embryo/h, respectively.
  
  
  CONCLUSIONS
  The increased level of pyruvate uptake during fertilization reflects the increased demand for energy necessary for the formation of the pronuclei. However, the metabolic measurements could not improve the selection of embryos with the best implantation potential. Finally, the reduction of glucose concentration in the culture medium failed to improve embryo viability.
authors.affiliation: Faculty of Medicine, Free University of Brussels, Erasme Hospital, Brussels, Belgium. fdevreke@med.ulb.ac.be
authors.forename: F
authors.initials: F
authors.lastname: Devreker
authors.forename: K
authors.initials: K
authors.lastname: Hardy
authors.forename: M
authors.initials: M
authors.lastname: Van den Bergh
authors.forename: J
authors.initials: J
authors.lastname: Winston
authors.forename: J
authors.initials: J
authors.lastname: Biramane
authors.forename: Y
authors.initials: Y
authors.lastname: Englert
mesh_terms: D010064:Embryo Implantation; D004622:Embryo, Mammalian / Q000378:metabolism*; D005260:Female; D005947:Glucose / Q000493:pharmacokinetics*; D006801:Humans; D008297:Male; D011247:Pregnancy; D011446:Prospective Studies; D019289:Pyruvic Acid / Q000493:pharmacokinetics*; D020554:Sperm Injections, Intracytoplasmic
chemical_list: D019289:Pyruvic Acid; D005947:Glucose