Objective: To investigate the relationship between endometrial thickness and volume with pregnancy rate after intrauterine insemination (IUI).

Methods: Transvaginal ultrasound examinations were performed on the day of hCG administration in 206 patients with ovarian hyperstimulation for IUI from April to June in 2008. Endometrial three-dimensional (3D) volume was assessed using virtual organ computer-aided analysis (VOCAL) by one investigator. Data was analyzed with SPSS program statistically.

Results: There was no difference in age, endometrial thickness, and volume between clomifene citrate and recombinant FSH groups. Endometrial mean thickness and volume were 10.61±2.65 mm and 5.23±2.67 mL, and correlation between endometrial thickness and volume was significant (Pearson correlation coefficient=0.74, p<0.01). Arcuate uterus did not show any difference in endometrial volume compared to normal uterus. Age was correlated to endometrial thickness and volume (Pearson correlation coefficient=-0.248 and -0.175, p<0.01). There was no significant difference in endometrial thickness and volume between pregnant and nonpregnant group.

Conclusion: Endometrial thickness can be simple and easy parameter in substitution for endometrial 3D volume in IUI cycles except severe uterine anomaly. But predictive values of endometrial thickness and volume for pregnancy are limited during IUI.