title: Characterization and prediction of IVF cycles generating "slow-cleaving" embryos.
abstract: OBJECTIVE
  To characterize and predict cycles generating open quote slow-cleaving closed quote embryos in in vitro fertilization, 86 cycles were retrospectively divided into two groups (open quote slow, closed quote n=41, and open quote fast, closed quote n=45) according to whether the number of blastomeres per embryo on day 3 was < or = or > than the mean of the distribution, respectively.
  
  
  RESULTS
  Cycles generating open quote slow-cleaving closed quote embryos were treated with luteinizing hormone-releasing hormone agonist before ovarian stimulation for a shorter period (12.1 +/- 0.5 versus 15.6 +/- 1.1 days; P < or = 0.01) and had higher immaturity grade of oocyte-corona-cumulus complexes which resulted in embryos (1.6 +/- 0.1 vs 1.3 +/- 0.1; P < or = 0.05) when compared to cycles producing "fast-cleaving" embryos. Both variables entered in a logistic regression model applied in order to predict the probability of a cycle generating "slow-cleaving" embryos (goodness-of-fit chi-square = 180.0, degrees of freedom (df) = 80, P = 0.4786). This model predicted correctly 86.7% (13 of 15) of cycles generating "slow-cleaving" embryos and 83.3% (10 of 12) of cycles producing "fast-cleaving" embryos when the estimated probability of a cycle producing "slow-cleaving embryos" was > or = 0.7 or < or = 0.3, respectively.
  
  
  CONCLUSIONS
  Shorter treatment with hormone-releasing hormone agonist before ovarian stimulation and higher immaturity grade of oocyte- corona-cumulus complexes which result in embryos are predictive characteristics of in vitro fertilization cycles generating "slow-cleaving" embryos.
authors.affiliation: Department of Pediatrics, Obstetrics, and Gynecology, Faculty of Medicine, Valencia University, Spain.
authors.forename: J J
authors.initials: JJ
authors.lastname: Tarin
authors.forename: J L
authors.initials: JL
authors.lastname: Romero
authors.forename: F
authors.initials: F
authors.lastname: Bonilla-Musoles
mesh_terms: D000328:Adult; D000375:Aging / Q000502:physiology; D002455:Cell Division / Q000502:physiology; D006063:Chorionic Gonadotropin / Q000494:pharmacology; D004624:Embryo Transfer / Q000379:methods* / Q000592:standards; D004622:Embryo, Mammalian / Q000166:cytology* / Q000502:physiology; D005314:Embryonic and Fetal Development / Q000502:physiology*; D004958:Estradiol / Q000097:blood; D005260:Female; D005298:Fertility / Q000502:physiology; D005307:Fertilization in Vitro / Q000379:methods* / Q000592:standards; D006801:Humans; D007246:Infertility / Q000209:etiology / Q000503:physiopathology; D008297:Male; D010060:Ovulation / Q000187:drug effects; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012661:Semen / Q000502:physiology; D013997:Time Factors
chemical_list: D006063:Chorionic Gonadotropin; D004958:Estradiol