We enrolled 317 consecutive patients from January 2011 to June 2012. At the second day of the menstrual cycle, a transvaginal ultrasound was performed to evaluate the antral follicle count and ovarian volume, and Doppler of both ovarian arteries was also performed. Controlled ovarian stimulation was performed and the patients were divided in two groups according to the result of the intrauterine insemination: group A (nonpregnant women) and group B (pregnant women).