Background: Intrauterine insemination (IUI) is a less expensive and less invasive treatment in comparison with other assisted reproductive techniques, and it has been widely used for a variety of indications as well as in the treatment of couples with infertility. The outcome of IUI may be affected by numerous factors but in this study, we evaluated the effects of cervical mucus removal undertaken before IUI on clinical pregnancy rates.
Methods : In this randomized clinical trial study, all infertile women who were candidates for IUI and attended Shahid Akbar Abadi Hospital during 2009 and 2010 were recruited. The participants were randomly assigned into two groups. Cervical mucus was removed prior to IUI in patients in group A but in group B, a classic IUI was done without removing the cervical mucus. Pregnancy rates were assessed in the two groups by serum levels of β-HCG and detection of fetus in the uterus. 
Results : 291 women including 143 in the classic IUI group and 148 in cervical mucus removal group completed the study. The pregnancy rates were 14.2% (21 pregnancies upon 148 cycles) in the cervical mucus removal group and 7% (10 pregnancies upon 143 cycles) in the control group (P=0.04, OR: 2.199; CI 95%: 0.997-4.85).
Conclusion: The findings showed that cervical mucus removal could result in a two-fold increase in pregnancy rate in comparison with classic IUI. Thus, we suggest this practical and noninvasive method to improve pregnancy rate in these patients.