Before the procedure urinary bladder must be empty. Initially internal genital organs (uterus, tubes and ovaries) are visuilized by transvaginal ultrasound. Afterwards small catheter is inserted into uterine cavity through cervical canal and contrast medium is entered through it. Using the contrast it is possible to better visuilize uterine cavity and its contours to exclude any intrauterine or developmental abnormlaitites (polyps, fibroids, uterine septum and etc). Movement of contrast into abdominal cavity is evaluated in real time and it helps to determine if fallopian tubes are blocked or patent. This procedure gives false positive results in 5-10% of cases (rare cases of spasm of fallopian tubes).