The HSG test: what it checks and what to expect

What an HSG checks

HSG stands for hysterosalpingography. It is an X-ray test that looks at two things:

• The fallopian tubes. An egg and sperm usually meet in a tube. If both tubes are blocked, they can't meet.
• The inside of the uterus. The test shows its shape, and can sometimes show a polyp, fibroid, scarring or a difference in shape a person was born with.

Tubes can be damaged by past pelvic infections, including chlamydia, by endometriosis, or by earlier surgery in the pelvis. Many people with blocked tubes have no symptoms, which is why the tubes are checked as part of a fertility evaluation.

When it is done

An HSG is usually booked after your period has finished and before you ovulate. There are two reasons for this timing:

• It avoids doing the test if you might already be in the early days of a pregnancy.
• The lining of the uterus is thin at this point, so the pictures are clearer.

You may be asked to avoid unprotected sex from the start of your period until the test, or to take a pregnancy test on the day. Call the centre if your period is late or very light that month.

Before the test

Caution. An HSG passes fluid through the cervix, which carries a small risk of carrying infection up into the tubes. Before the test, you may be offered a swab test for chlamydia, or antibiotics. Tell the team if you have unusual discharge, pelvic pain or a fever, as the test may need to wait.

Also tell the team if:

• you have ever reacted to X-ray contrast dye, or have a serious allergy
• you have had a pelvic infection before
• you might be pregnant

Your doctor may suggest taking a simple painkiller a little while before the test. Ask them what is suitable for you. It helps to have someone come with you, and to plan a quiet rest of the day.

How it is done

1. You lie on an X-ray table with your knees bent, as for a smear test.
2. A speculum is placed in the vagina so the cervix can be seen, and the cervix is cleaned.
3. A thin, soft tube is passed through the cervix.
4. A special dye (contrast) is gently passed through the tube into the uterus.
5. X-ray pictures are taken as the dye fills the uterus and, if the tubes are open, spills out of their ends.

The whole procedure usually takes around 10 to 15 minutes, and the dye part only a few minutes. The dye is absorbed by your body.

What it feels like

People's experiences vary a lot, and it is fair to be honest about this. Many people feel cramping, like period pain, while the dye goes in. For some it is mild; for others it is strong for a short time. The cramps usually settle within minutes to a few hours.

Afterwards, it is common to have:

• some sticky discharge as the dye comes out
• light spotting for a day or two
• mild cramps

You can usually go back to normal activities the same day or the next day.

Good to know. A tube can sometimes look blocked on an HSG when it isn't, because it went into a brief spasm during the test. If a blockage is seen, your doctor may suggest another test to confirm it before making any decisions.

Alternatives to an HSG

Test	How it works	Points to know
HSG	X-ray with contrast dye	Widely available; uses a small dose of X-rays
HyCoSy or sono-HSG	Ultrasound with a contrast fluid or foam, through the cervix	No X-rays; also shows the ovaries and uterus on the same scan
Laparoscopy with dye	Keyhole surgery under general anaesthetic	Usually for people with a known reason, such as suspected endometriosis, a past pelvic infection or ectopic pregnancy; problems can sometimes be treated at the same time

Which test is offered depends on your history and what is available locally. Celova does not perform any of these tests, but a doctor can talk you through which one suits your situation.

When to see a doctor

Some discomfort is expected. Seek medical help if, in the days after the test, you have:

• a fever or chills
• pain that gets worse instead of better, or that painkillers don't help
• smelly or unusual discharge

These could be signs of an infection, which needs prompt treatment.

Call 112 or go to the nearest hospital if you have severe pain, heavy bleeding (soaking a pad within an hour), or you feel faint or collapse.