title: Comparison of pregnancy rate between fresh embryo transfers and frozen-thawed embryo transfers following ICSI treatment.
abstract: BACKGROUND
  The use of assisted reproductive technology (ART) is increasing in the world. The rate, efficacy and safety of ART are very different among countries. There is an increase in the use of intra cytoplasmic sperm injection (ICSI), single fresh embryo transfer (ET) and frozen-thawed embryo transfer (FET).
  
  
  OBJECTIVE
  The objective of this study was to compare pregnancy rate in fresh ET and FET.
  
  
  METHODS
  In this retrospective cross-sectional study 1014 ICSI-ET cycles (426 fresh ET and 588 FET) from 753 women undergoing ICSI treatment referred to Fatemezahra Infertility and Reproductive Health Research Center in Babol, Iran from 2008 to 2013 were reviewed.
  
  
  RESULTS
  There were no significant differences between biochemical pregnancy rate (23% versus 18.8%, OR 1.301; 95% CI .95-1.774), gestational sac (95.6% versus 100% in FET, OR 0.60; 95% CI 0.54-0.67), and fetal heart activity (87.2% versus 93.6% OR .46; 95% CI .16-1.32) in fresh ET and FET cycles, respectively. P< 0.05 was considered statistically significant for all measures.
  
  
  CONCLUSIONS
  Although, the result showed no significantly difference between the fresh ET and the FET cycles, however the embryos are able to be stored for subsequent ART. Therefore, we recommend FET cycles as an option alongside the fresh ET.
authors.affiliation: Infertility and Reproductive Health Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran.
authors.forename: Zahra
authors.initials: Z
authors.lastname: Basirat
authors.affiliation: Department of Midwifery, Infertility and Reproductive Health Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran.
authors.forename: Hajar
authors.initials: H
authors.lastname: Adib Rad
authors.affiliation: Infertility and Reproductive Health Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran.
authors.forename: Sedigheh
authors.initials: S
authors.lastname: Esmailzadeh
authors.affiliation: Infertility and Reproductive Health Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran.
authors.forename: Seyed Gholam Ali
authors.initials: SG
authors.lastname: Jorsaraei
authors.affiliation: Department of Social Medicine and Health, Babol University of Medical Sciences, Babol, Iran.
authors.forename: Karimollah
authors.initials: K
authors.lastname: Hajian-Tilaki
authors.affiliation: Department of Midwifery, Infertility and Reproductive Health Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran.
authors.forename: Hajar
authors.initials: H
authors.lastname: Pasha
authors.affiliation: Infertility and Reproductive Health Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran.
authors.forename: Faeze
authors.initials: F
authors.lastname: Ghofrani
keywords: Cryopreservation; Embryo transfer; Intra cytoplasmic sperm injection; Pregnancy rate