title: In vitro development and pregnancy outcomes for human embryos cultured in either a single medium or in a sequential media system.
abstract: OBJECTIVE
  To compare a single medium, with medium renewal on day 3, with a sequential media system for development of human embryos to the blastocyst stage and subsequent pregnancy outcome.
  
  
  METHODS
  Prospectively randomized study using donor oocytes.
  
  
  METHODS
  Private infertility clinic.
  
  
  METHODS
  Oocytes were collected from 47 donors (mean +/- SD age = 25.6 +/- 3.5 years) from March to October 2006 and used for 79 patients (40.6 +/- 5.4 years). The patients were prospectively randomized to have their embryos cultured in a single medium or in a sequential media system.
  
  
  METHODS
  The donor oocytes were fertilized with fresh patient partner sperm and the resultant zygotes cultured in either a single medium or a sequential media system from day 1 until the blastocyst stage. After endometrial preparation the embryos were transferred to the patients on day 5 or day 6.
  
  
  METHODS
  In vitro embryo developmental characteristics and pregnancy and implantation rates.
  
  
  RESULTS
  In vitro development rates on days 3, 4, and 5 and implantation rates were significantly greater for embryos cultured in the single medium than for those cultured in the sequential media system.
  
  
  CONCLUSIONS
  A single medium was as good as or better than a sequential media system for human embryo culture from the zygote to blastocyst stage. The idea that a sequential media system is required for optimal development of the human embryo to the blastocyst stage is highly questionable.
authors.affiliation: Grupo PRANOR, Instituto de Ginecología y Reproducción, Lima, Perú. soledads@fertilidadperu.com
authors.forename: Soledad
authors.initials: S
authors.lastname: Sepúlveda
authors.forename: Javier
authors.initials: J
authors.lastname: Garcia
authors.forename: Elard
authors.initials: E
authors.lastname: Arriaga
authors.forename: Julio
authors.initials: J
authors.lastname: Diaz
authors.forename: Luis
authors.initials: L
authors.lastname: Noriega-Portella
authors.forename: Luis
authors.initials: L
authors.lastname: Noriega-Hoces
mesh_terms: D000328:Adult; D001755:Blastocyst / Q000502:physiology; D003470:Culture Media; D046149:Embryo Culture Techniques; D010064:Embryo Implantation; D047108:Embryonic Development; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D008875:Middle Aged; D011247:Pregnancy; D011256:Pregnancy Outcome; D011446:Prospective Studies
chemical_list: D003470:Culture Media