HSG: It is the 1st line fertility investigation to a women to asses her fallopian tubes and uterus. Tubal blocks, hydrosalphinx, tubal and uterine anomalies can be detected . HSG is an X-ray based test, which is an outpatient procedure where iodine based constant dye, is injected into the cervix & uterus. If tubes are open constant dye will fill the tubes then spill from the ends.