title: [Success' determinant variables in assisted reproduction].
abstract: OBJECTIVE
  To perform a statistical analysis with variables that have influence on pregnancy rates to establish a prognostic factor of each one.
  
  
  METHODS
  We performed a retrospective, descriptive, and observational study with 240 patients that underwent to IVF-ET program. The analyzed variables were: infertility factor, ovarian stimulation protocol, age of patients, basal hormonal levels, oestradiol preovulatory levels, endometrial characteristics, fertilization rate, number and quality of oocytes, number and quality of embryos, and difficulty of the embryo transfer.
  
  
  RESULTS
  The mean age of the patients was 34 +/- 4.42 years old. Tubal and pelvic pathologies were the main infertility cause. During the statistical analysis we observed that the only variables with differences regarding pregnancy were the number of cells in the embryo (7.18 vs 5.9), the fertilization rate (58.3 vs 50.1%), and the number of transferred embryos. With the logistic regression analysis we observed that the number of cells on each embryo had a relative risk of 1.37 (CI 95%; 1.15-1.63), and that the number of transferred embryos had one of 1.63 (CI 95%; 1.10-1.58).
  
  
  CONCLUSIONS
  There are many variables that influence the pregnancy rates, but with our results we consider that the embryo quality, its characteristics and the number of transferred embryos could predict better the possibilities of pregnancy in IVF-ET programs.
authors.affiliation: Unidad de Reproducción Asistida, Centro Especializado para la Atención de la Mujer, Hospital Angeles de la Lomas. drjruiz@prodigy.net.mx
authors.forename: Julián
authors.initials: J
authors.lastname: Ruiz Anguas
authors.forename: Esperanza
authors.initials: E
authors.lastname: Carballo Mondragón
authors.forename: Leonor
authors.initials: L
authors.lastname: Durán Monterrosas
authors.forename: Alberto
authors.initials: A
authors.lastname: Kably Ambe
mesh_terms: D000328:Adult; D001755:Blastocyst / Q000166:cytology; D004624:Embryo Transfer / Q000379:methods / Q000706:statistics & numerical data*; D004717:Endometrium / Q000648:ultrastructure; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods / Q000706:statistics & numerical data*; D012739:Gonadal Steroid Hormones / Q000097:blood; D006801:Humans; D007247:Infertility, Female / Q000209:etiology; D008800:Mexico; D009865:Oocytes / Q000166:cytology; D010062:Ovulation Induction / Q000379:methods; D011247:Pregnancy; D011256:Pregnancy Outcome; D018873:Pregnancy Rate; D011272:Pregnancy, Multiple; D012189:Retrospective Studies
chemical_list: D012739:Gonadal Steroid Hormones