title: [Analyses of the factors affecting the occurrence of polypronuclear embryos in in-vitro fertilization and embryo transfer].
abstract: OBJECTIVE
  To investigate the factors affecting the occurrences of the polypronuclear embryos in in-vitro fertilization and embryo transfer (IVF-ET).
  
  
  METHODS
  The data from 145 IVF-ET cycles and 1,168 oocytes were analyzed by logistic regression for multiple factors. The influences of the couple's age, the superovulation stimulation protocols, the number of the follicles punctured and the oocytes obtained, the preinseminational interval, the quality and quantity of seminal and inseminational sperms, and the oocyte fertilization ratio on the incidences of the polypronuclear embryos from the matured, and immature oocytes were examined respectively.
  
  
  RESULTS
  The incidence of the polypronuclear embryos from matured oocytes was significantly negatively correlated with the women age and the number of the follicles punctured, and the incidence from immature oocytes was significantly positively correlated with the density of sperms at grade a and b and the oocyte fertilization ratio.
  
  
  CONCLUSIONS
  The woman's age and the number of follicles are the main factors which influence the occurrence of polypronuclear embryos from matured oocytes, while the density of the seminal sperm with high motility and the fertilization ratio play important roles in the occurrence of polypronuclear embryos in immature oocytes. Stimulating greater number of follicles might be benefit for the reduction of occurrence of polypronuclear embryos.
authors.affiliation: Affiliated Obstetrics and Gynecology Hospital, Faculty of Medicine Zhejiang University, Hangzhou 310006.
authors.forename: F
authors.initials: F
authors.lastname: Jin
authors.forename: Y
authors.initials: Y
authors.lastname: Shi
authors.forename: F
authors.initials: F
authors.lastname: Zhou
mesh_terms: D004624:Embryo Transfer; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D008297:Male; D009865:Oocytes; D010062:Ovulation Induction; D011123:Polyploidy; D012044:Regression Analysis