title: Prognostic value of three pro-nuclei (3PN) incidence in elective single blastocyst-stage embryo transfer.
abstract: OBJECTIVE
  To investigate whether 3PN incidence could lead to a worse pregnancy outcome of elective single blastocyst stage embryo transfer (eSBET).
  
  
  METHODS
  This study included 706 eSBET cycles from January 2013 to March 2015. The patients were divided into two groups as follows: group 1 included 286 patients with no 3PN zygotes and group 2 included 420 patients with 3PN zygotes.
  
  
  METHODS
  female age, endometrial thickness, infertility duration, type of infertility, main etiology of infertility, clinical pregnancy and abortion rate.
  
  
  RESULTS
  We observed that there was no significant difference in female age, endometrial thickness, infertility duration and abortion rate between two groups. It's worth noting that the clinical pregnancy rate in 3PN > 0% group was significantly lower than 3PN = 0 group (P = 0.021).
  
  
  CONCLUSIONS
  3PN incidence might make anegative effect on pregnancy outcomes in elective single blastocyst stage embryo transfer.
authors.affiliation: The ART Center, Northwest Women's and Children's Hospital Xi'an 710003, China.
authors.forename: Mingzhao
authors.initials: M
authors.lastname: Li
authors.affiliation: The ART Center, Northwest Women's and Children's Hospital Xi'an 710003, China.
authors.forename: Wanqiu
authors.initials: W
authors.lastname: Zhao
authors.affiliation: The ART Center, Northwest Women's and Children's Hospital Xi'an 710003, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.affiliation: The ART Center, Northwest Women's and Children's Hospital Xi'an 710003, China.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Zhao
authors.affiliation: The ART Center, Northwest Women's and Children's Hospital Xi'an 710003, China.
authors.forename: Juanzi
authors.initials: J
authors.lastname: Shi
keywords: 3PN; pregnancy; single blastocyst