An HSG is part of your fertility workup. It is used to see if your fallopian tubes are open (patent) and if the uterine cavity is normal. A clear fluid called contrast medium is slowly infused into your uterus and tubes while images are taken using x-rays.

• Why check the fallopian tubes?  Tubal blockages can stop sperm from reaching the egg and prevent fertilisation (see image below). At least one patent tube is needed for spontaneous fertilisation.
• Why check the uterine cavity?  Uterine abnormalities may also lead to fertility issues such as abnormal shape, adhesions, benign tumors, etc.

The sperm journey to the egg & fertilization