Objective        To evaluate the impact of gonadotrophin releasing hormone agonist (GnRH-a) on the outcome of frozen-thawed embryo transfer (FET).       Methods        A total of 507 FET treatment cycles performed in our department from June 2012 to October 2013 were collected and retrospectively analyzed. The patients were identified as 2 groups

group A (n=60) receiving GnRH-a in the treatment cycle whereas group B (n=447) not. The age of the patients

etiology of female infertility

endometrial thickness on the day of progesterone ini

tiation day

the number of transferred embryos

clinic pregnancy rate and multiple pregnancy rate were compared between the 2 groups.       Results        There was no significant difference in the age

endometrial thickness on the day of progesterone initiation and the number of the embryos transferred between the 2 groups

but the clinical pregnancy rate was significantly higher in group A than group B (58.34% vs 43.40%

P

0.05). In addition

the embryonic diapause and ectopic pregnancy rates were lower in group A than group B. In the pelvic tubal factor patients

the clinic pregnancy rate was obviously increased after GnRHa pretreatment (

P

0.05).       Conclusion        GnRH-a pretreatment improves endometrial receptivity in FET cycles

and is helpful for early embryo transfer

especially for the pelvic tubal infertility.