Introduction:
Because of benefits of IUI than IVF and other methods of threatment of infertilety and becouse infertility with unknown cause and therapeutic intervention are still controversial topics that still embryonic problems and failed implantation are considered its risk factors. Therefore, the objective of this study was to investigate the effect of endometrial scratch on the success of IUI cycle. This investigation evaluation the implantation of emberion in endometrial cavity after injury of endometr.

Methodology:
In this randomized clinical trial study conducted in infertility clinic in the Shahid Ayatollah Beheshti Hospital, 180 women aged 18 to 40 years who suffered from infertility were randomly divided into three groups: 1. control group only IUI (n=60), 2. The treatment group one cycle before IUI under endometrial scratch (n = 60), and 3. Treatment group in IUI cycle endometrial scratch (n = 60). Endometrial scratch was performed by feeding tube and IUI through cutter. For statistical analysis, Kruskal-Wallis test and chi-square test were used.

Results:
The prevalence of pregnancy in the third group (in IUI cycle under endometrial scratch) was n = 12, 20.7%, and it was n = 11, 18.00% in the second group (one cycle before IUI under endometrial scratch), which it was higher compared to control group (n=6, 10.2%), but the difference was not statistically significant (P=0.27). Additionally, there was no significant relationship between fertility rate in different groups and patient’s age (P=0.88), duration of infertility (p=0.69) and type of infertility (P=0.18).

Discussion and conclusion:
The results of this study although were not significant, as the frequency of pregnancy in the two groups under endometrial scratch was higher compared to the control group, it seems that this lack of significance to be due to the small sample size and local mechanical endometrial scratch increased endometrial receptivity and facilitated the embryo implantation.