title: Human oocyte maturity in vivo determines the outcome of blastocyst development in vitro.
abstract: OBJECTIVE
  To date, the impact of oocyte maturity at aspiration on the blastocyst formation in vitro has not been fully evaluated. This study was undertaken to assess the influence of oocyte maturity in patients undergoing in vitro fertilization and blastocyst transfer program.
  
  
  METHODS
  A total of 1278 oocytes derived from 147-IVF cycles were retrospectivly analyzed. Oocyte maturity was graded on a scale from 1 to 5 based on the morphology of the ooplasm, cumulus mass, corona radiata, and membrana granulosa cells.
  
  
  RESULTS
  Mature oocytes yielded the highest fertilization rates. Although the cleavage rates were similar in both groups, the percentage of poor morphology, day-3 embryos from the nonmature-oocyte group was significantly higher than from the mature-oocyte group (54.7% vs. 15.5%, P < 0.001). Although good morphology, day-3 embryos were collected from nonmature oocytes, the incidence of these embryos developing to the blastocyst stage was significantly less than from mature oocytes (33.3% vs. 71.2%, P < 0.001). Although blastocyst stage embryos were collected from nonmature oocytes, the incidence of these embryos developing to the top-scoring blastocysts was significantly less than from mature oocytes (58.3% vs. 89.5%, P < 0.001).
  
  
  CONCLUSIONS
  These phenomena suggest that oocyte maturity produced in vivo determine the fertilization potential and subsequent blastocyst quality in vitro.
authors.affiliation: Department of Obstetrics and Gynecology, Chang Gung Memorial Hospital, Kaohsiung, Taiwan.
authors.forename: Yi-Chi
authors.initials: YC
authors.lastname: Lin
authors.forename: Shiuh-Young
authors.initials: SY
authors.lastname: Chang
authors.forename: Kuo-Chung
authors.initials: KC
authors.lastname: Lan
authors.forename: Hsuan-Wei
authors.initials: HW
authors.lastname: Huang
authors.forename: Chih-Yang
authors.initials: CY
authors.lastname: Chang
authors.forename: Meng-Yin
authors.initials: MY
authors.lastname: Tsai
authors.forename: Fu-Tsai
authors.initials: FT
authors.lastname: Kung
authors.forename: Fu-Jen
authors.initials: FJ
authors.lastname: Huang
mesh_terms: D001755:Blastocyst / Q000502:physiology*; D004624:Embryo Transfer; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D066298:In Vitro Techniques; D009865:Oocytes / Q000502:physiology*; D011247:Pregnancy