title: Zygote intrafallopian tube transfer versus intrauterine cleavage or blastocyst stage transfer after intracytoplasmic sperm injection cycles in patients with repeated implantation failure: A prospective follow-up study.
abstract: OBJECTIVE
  This study aimed to compare the outcomes between zygote intrafallopian transfer (ZIFT) with intrauterine day-3 (cleavage stage) embryo transfer and intrauterine day-5 (blastocyst stage) embryo transfer in patients undergoing intracytoplasmic sperm injection.
  
  
  METHODS
  This prospective study was performed at Royan Institute, Tehran, Iran, between January 2012 and January 2014. Two hundred fifty women with more than three unexplained implantation failures were divided non-randomly into three groups according to embryonic age and methods used as follows: (i) intrauterine cleavage-stage embryo transfer (n = 100); (ii) intrauterine blastocyst-stage embryo transfer (n = 50); and (iii) ZIFT (n = 100). Implantation, clinical pregnancy, miscarriage and live birth rates were our main outcomes.
  
  
  RESULTS
  Patients' characteristics and ovarian response were comparable among the three groups. Implantation rate (56.1% vs 27.9%) was significantly higher in the blastocyst group as compared to the ZIFT group; however, clinical pregnancy rate (38% vs 23%) was not statistically significantly different between the two groups, but due to the significantly higher miscarriage rate (34.7% vs 5.3%) in the ZIFT group, the live birth rate was significantly higher in the blastocyst group (P = 0.04). No significant differences were found between the cleavage-stage and blastocyst-stage groups in terms of implantation, clinical pregnancy, miscarriage and live birth rates.
  
  
  CONCLUSIONS
  We do not recommend the use of the ZIFT procedure for patients with repeated implantation failures. It seems that replication of cleavage- or blastocyst-stage embryo transfer is more efficient and affordable.
authors: Departments of Endocrinology and Female Infertility.|Obstetrics and Gynecology Department, Faculty of Medicine, Tehran University of Medical Science, Tehran, Iran.
authors: Ensieh
authors: E
authors: Shahrokh Tehraninejad
authors: Obstetrics and Gynecology Department, Faculty of Medicine, Tehran University of Medical Science, Tehran, Iran.
authors: Elham
authors: E
authors: Azimi Nekoo
authors: Departments of Endocrinology and Female Infertility.
authors: Firouzeh
authors: F
authors: Ghaffari
authors: Departments of Endocrinology and Female Infertility.
authors: Maryam
authors: M
authors: Hafezi
authors: Embryology at Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR.
authors: Leila
authors: L
authors: Karimian
authors: Departments of Endocrinology and Female Infertility.
authors: Arezoo
authors: A
authors: Arabipoor
mesh_terms: D000022:Abortion, Spontaneous; D000328:Adult; D004624:Embryo Transfer; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D011247:Pregnancy; D011256:Pregnancy Outcome; D018873:Pregnancy Rate; D011446:Prospective Studies; D020554:Sperm Injections, Intracytoplasmic; D017211:Treatment Failure; D016896:Treatment Outcome; D017388:Zygote Intrafallopian Transfer
keywords: blastocyst-stage embryo; cleavage-stage embryo; intracytoplasmic sperm injection outcome; zygote intrafallopian transfer