Checking the uterus before treatment: what these tests are looking for

Fertility conversations tend to concentrate on eggs and sperm, which makes sense — they are where most of the numbers are. But a transfer only works if there is somewhere for an embryo to implant, and a distinct set of tests exists to look at that.

These are the ones people understand least, partly because the names are unfamiliar and partly because they are usually explained in a single sentence on a to-do list.

What is being looked at

Three things, broadly: the shape of the uterine cavity, whether anything is occupying it, and how the lining behaves.

Shape. Some people have a uterus that formed differently — a septum, or another structural variation. Many are found incidentally and never caused symptoms. Whether one matters for treatment depends on what it is.

Occupants. Fibroids, polyps and scar tissue are all common. Whether any of them matters depends mostly on where it sits: something inside the cavity is a different question from something in the wall that never intrudes on it.

The lining. How the endometrium thickens and responds through a cycle, which becomes the focus during transfer preparation.

The tests you may be offered

Transvaginal ultrasound. The starting point, and part of almost every workup. Looks at the uterus and ovaries, and is also the tool used repeatedly during monitoring.

Saline infusion sonography (sometimes called a sonohysterogram). Sterile fluid is placed in the cavity during an ultrasound, which separates the walls and makes the inside far easier to see. Better than ultrasound alone at finding polyps and small fibroids. Usually quick, sometimes crampy, no anaesthetic.

Hysterosalpingogram (HSG). A contrast study, usually X-ray, that shows the cavity and whether the tubes are open. Often the test that answers the tubal question. Cramping is common; clinics usually advise taking pain relief beforehand.

Hysteroscopy. A thin camera passed through the cervix to look directly inside. The most definitive of the four, and the only one where something found can often be treated in the same session. Done awake or under sedation depending on the setting and what is expected.

Which of these you are offered depends on your history and on what earlier tests showed. If you are offered one and are not sure why, that is a good question to ask rather than a formality to get through.

Why this gets done before rather than after

Two reasons.

The first is straightforward: if something in the cavity is going to be addressed, it is better addressed before an embryo is transferred than after a transfer has not worked.

The second is about sequence. If a procedure is needed, it has a recovery period and it affects when a cycle can start. Discovering that late adds a month or more to a timeline that was already longer than most people expect — which is the broader point of how long treatment actually takes.

If something is found

Most findings fall into one of three categories, and it is worth asking which yours is:

• Worth treating before a transfer, because it is likely to matter.
• Worth watching, but not worth a procedure right now.
• Incidental, and not relevant to your plan.

Plenty of findings sit in the second and third categories. “They found a fibroid” is not one piece of information, it is the beginning of a question, and the useful follow-up is does this one matter for me, and why.

If a procedure is recommended, ask what it involves, how long recovery takes, and when a cycle could start afterwards. Those three answers convert a worrying finding into a scheduling fact.

If you are treating abroad

Ask what the clinic wants done before you arrive. Some of these tests are easier to arrange at home, and arriving without them can cost you a cycle. The reasoning is the same as in the tests to have done before you travel.

Bring images, not just reports. Where possible, bring the actual imaging files rather than a written summary. A clinic reading the pictures themselves is in a better position than one reading someone else’s description of them.

Ask who would perform a procedure if one is needed, and whether that changes your travel. A hysteroscopy added to the plan is another trip or a longer stay.

This article is general information, not medical advice. Which tests you need, and what any finding means for you, are questions for the clinician assessing your case.

For how the workup fits into the wider process, read the patient journey.