title: Routine blastocyst culture and transfer: 201 patients' experience.
abstract: OBJECTIVE
  The purpose was to compare the outcomes between day-5 blastocyst and day-2 embryo transfers.
  
  
  METHODS
  Infertile women who accepted the ovarian hyperstimulation and oocyte retrieval were divided: Group 1, day 2 embryo transfer, group 2, cultured to day 5 in serum-free sequential culture medium and transfer. Early embryo quality and growth, blastocyst formation and quality, implantation rate (IR) and pregnancy rates (PR) were detected.
  
  
  RESULTS
  Total blastocyst formation rate was 49.4%. Better early embryo quality (days 2, 3) and higher day 3 blastomere number possess higher blastocyst formation rate. The IR for day 2 and day 5 embryos were 10.8% and 22.2%, respectively. The PR in both groups were comparable (37.3% vs. 41.8%).
  
  
  CONCLUSIONS
  Blastocyst transfer has higher IR and comparable PR as those of day 2 embryo transfer. Early embryo qualities and day 3 blastomere number are useful in predicting the final blastocyst formation. Blastocyst formation rate is not related to maternal age, infertile causes, insemination methods, and early embryo number.
authors.affiliation: Department of Obstetrics and Gynecology, China Medical College Hospital, Taichung, Taiwan.
authors.forename: Y Y
authors.initials: YY
authors.lastname: Hsieh
authors.forename: H D
authors.initials: HD
authors.lastname: Tsai
authors.forename: F C
authors.initials: FC
authors.lastname: Chang
mesh_terms: D000328:Adult; D001755:Blastocyst / Q000166:cytology* / Q000502:physiology; D002452:Cell Count; D046508:Culture Techniques / Q000379:methods*; D010064:Embryo Implantation / Q000502:physiology*; D004624:Embryo Transfer / Q000379:methods*; D004622:Embryo, Mammalian / Q000166:cytology / Q000502:physiology; D005260:Female; D006801:Humans; D008423:Maternal Age; D011247:Pregnancy; D018873:Pregnancy Rate; D018566:Pregnancy, High-Risk; D019233:Retreatment; D013997:Time Factors