The tube test you're dreading, told plainly.

An HSG test is an X-ray that shows whether your fallopian tubes are open and whether the inside of your womb has a normal shape.

The egg and sperm meet inside the tube, and the embryo travels down it to the womb. If both tubes are blocked, tracking ovulation or IUI cannot work, and IVF is the route because it bypasses the tubes. If one tube is open, natural pregnancy and IUI are still possible. That difference is why the test is done rather than guessed.

A thin tube is passed through the cervix, a dye goes in slowly over a minute or two, and X-ray pictures are taken; most women feel cramping like a strong period for a few minutes.

You lie with your knees bent, a speculum is placed as for a smear test, and the cervix is cleaned. There is no anaesthetic and no cut. A few women find it sharply painful: say so straight away, because slowing the dye usually helps. Light spotting and a sticky discharge for a day or two are normal. Fever, heavy bleeding or pain that gets worse after 24 hours needs a same-day check: call us on +91 89399 94244; outside clinic hours, call 108 or go to the nearest emergency department, then call us.

The test is done after your period stops and before you ovulate, usually between day 6 and 11 of the cycle.

Bleeding would blur the pictures, and testing before ovulation means there is no chance of an early pregnancy being present. The appointment is booked by counting from day 1 of your period. If your period comes early or late, tell us and we move it. It is also postponed if you might be pregnant, have a pelvic infection or are bleeding heavily.

A tube test shows whether the tubes are open, not whether they work well inside, and it does not show endometriosis, adhesions outside the tubes or the ovaries.

The fine hairs that move the egg along cannot be seen on X-ray or ultrasound. A tube can also look blocked when it is only in spasm at the point where it joins the womb. One unexpected result is a reason to repeat or cross-check, not to conclude.

All three ask the same question; they differ in how they see: X-ray (HSG), ultrasound (HyCoSy with saline, HyFoSy with foam gel), or a camera under anaesthetic (laparoscopy).

NICE advises HSG as the first test for women with no history of pelvic infection, surgery or endometriosis, with HyCoSy an alternative where the expertise exists. HyCoSy and HyFoSy avoid X-ray and iodine and show the ovaries at the same time. Laparoscopy is surgery, so it is kept for suspected endometriosis, past pelvic infection or surgery, or an unclear first test, and it can treat what it finds.