title: Rate of blastocyst development from excess embryos remaining in culture after day 3 embryo transfer.
abstract: OBJECTIVE
  To assess the rate of blastocyst development (BDR) from embryos remaining in culture after day-3 embryo transfer (ET), and its relationship to cause of infertility.
  
  
  METHODS
  Retrospective cohort study in tertiary-care IVF Center. Blastocyst development rate (BDR) after day-3 ET was assessed in 126 women who underwent either conventional IVF or ICSI.
  
  
  RESULTS
  Mean age, early follicular FSH levels, number of 2PN zygotes, number of excess embryos, and number of ET were similar between patients that underwent IVF and ICSI. Overall, 20% of extra embryos from conventional IVF patients developed into blastocysts compared to 14% of embryos obtained from ICSI. Cause of infertility did not affect BDR, even in patients who required ICSI due to male factors.
  
  
  CONCLUSIONS
  Low rates of blastocyst development from excess embryos are similar between IVF and ICSI patients. Only 15 to 25% of excess embryos left in culture develop into blastocysts, regardless of cause of infertility. Physicians and patients can use this information to adjust both AR treatment protocols and patient expectations.
authors.affiliation: University of Pennsylvania, Department of Obstetrics and Gynecology, Division of Reproductive Medicine and Surgery, Philadelphia, PA, USA. mdayal@mfa.gwu.edu
authors.forename: Molina B
authors.initials: MB
authors.lastname: Dayal
authors.forename: George
authors.initials: G
authors.lastname: Kovalevsky
authors.forename: Pasquale
authors.initials: P
authors.lastname: Patrizio
mesh_terms: D000328:Adult; D001755:Blastocyst / Q000502:physiology; D015331:Cohort Studies; D046508:Culture Techniques; D004624:Embryo Transfer / Q000706:statistics & numerical data*; D047108:Embryonic Development / Q000502:physiology*; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods / Q000706:statistics & numerical data*; D006801:Humans; D011247:Pregnancy; D018873:Pregnancy Rate; D012189:Retrospective Studies; D020554:Sperm Injections, Intracytoplasmic / Q000379:methods / Q000706:statistics & numerical data*; D018709:Statistics, Nonparametric