title: Gonadotropin-releasing hormone agonist for oocyte triggering in endometrial preparation of letrozole stimulation protocols does not affect clinical outcome of frozen-thawed embryo transfer.
abstract: OBJECTIVE
  This study aims to evaluate the effectiveness of GnRH agonist in comparison with hCG for triggering final oocyte maturation in endometrial preparation of letrozole stimulation protocols for frozen-thawed embryo transfer.
  
  
  METHODS
  The frozen-thawed embryo transfer cycles (FET) that use the letrozole stimulation protocols for endometrial preparation were divided into two groups according the different method of triggering final oocyte maturation. The serum LH and E2 levels, and the endometrial thickness on the day of triggering, the clinical pregnancy rates, the miscarriage rates and live birth rates were compared.
  
  
  RESULTS
  There were no significant differences in the age, the endometrial thickness, the number of embryos transferred between the two groups. The clinical pregnancy rate, abortion rate and live birth rates of the group A were similar compared with the group B, P<0.05.
  
  
  CONCLUSIONS
  Using GnRH agonist for oocyte triggering in endometrial preparation of letrozole stimulation protocols for frozen-thawed embryo transfer does not affect the clinical outcome compared with hCG under the same luteal phase support.
authors.affiliation: Department of Reproductive Medicine, Liuzhou Maternity and Child Healthcare Hospital Guangxi Province, 545001, China.
authors.forename: Pin-Xiu
authors.initials: PX
authors.lastname: Huang
authors.affiliation: Department of Reproductive Medicine, Liuzhou Maternity and Child Healthcare Hospital Guangxi Province, 545001, China.
authors.forename: Ji-Hong
authors.initials: JH
authors.lastname: Wei
authors.affiliation: Department of Reproductive Medicine, Liuzhou Maternity and Child Healthcare Hospital Guangxi Province, 545001, China.
authors.forename: Li-Hong
authors.initials: LH
authors.lastname: Wei
keywords: Gonadotropin-releasing hormone agonist; frozen-thawed embryo transfer; hCG; letrozole