The womb has two fallopian tubes that connect to the ovaries in the pelvis. When the ovaries release an egg the fallopian tubes are responsible for gathering the egg and directing it towards the womb. On route if sperm is present the egg may fertilise before developing into and embryo and travelling on to implant in the womb lining (endometrium). A woman with infertility may have damaged or blocked fallopian tubes. A test to check that the fallopian tubes are working can be performed in most fertility clinics.
One way to check tubal patency is by ultrasound Hysterosalpingo-contrast-sonography (HyCoSy). This involves pushing foam though a slim catheter inside the womb which then flows through the fallopian tubes if they are open. An ultrasound HyCoSy test is performed while the woman is awake and is usually very well tolerated but it can cause some discomfort. The ultrasound scan detects if the foam is flowing freely through the womb and tubes.
Alternatively an HSG (Hysterosalpingogram) can be performed in a hospital radiology department. The HSG involves inserting a catheter into the womb through the cervix, while a series of x-ray pictures are taken as radio-opaque dye is pushed through the catheter. The outline of the womb and fallopian tubes is seen on the x-ray image.