Tubal Patency Ultrasound (HyCoSy)

Tubal Patency Ultrasound (HyCoSy)

A tubal patency ultrasound checks whether your fallopian tubes are open or blocked.  It is a low risk procedure which is performed in the ultrasound room and is the ideal test for checking the shape of the uterine cavity and tubal patency and can direct the type of treatment that is required for women having trouble falling pregnant.

Technical Aspects

Your doctor may call a tubal patency assessment a HyCoSy. This stands for hysterosalpingo-contrast-sonography and is the technical name for the procedure.


Difficulty falling pregnant is common and may be due to tubal blockage which can be caused by previous tubal infection, adhesions or conditions such as endometriosis.

How is a Tubal Patency Study Performed?

It starts with a normal ultrasound (using a vaginal probe) to assess your uterus, ovaries and pelvis. This is followed by a doctor inserting a small tube into your uterus. The tube is very small (around 1mm width) however it is possible to get some crampy period like pain during insertion. For this reason we ask patients to take an anti-inflammatory tablet (such as two ibuprofen) 1 hour before the procedure. If the patient has been told not to take anti-inflammatory tablets (for example they have an allergy, gastric oesophageal reflux or asthma which reacts to this type of medication) they could take paracetamol with or without some codeine (eg Panadeine).

The small tube is used to inject a small amount of saline (sterile water) into the uterus. This allows us to accurately assess the shape of the cavity of the uterus and whether there is anything protruding into the cavity (such as a polyp or fibroid).

The final part of the procedure is to watch the saline flow through the fallopian tubes.

When can a tubal patency study be performed?

You must be referred by your doctor for this test. It will not be performed when you are bleeding  or in the second half of your cycle  if there is any chance you could be pregnant. You will be asked the date of your last period when you book the ultrasound.

How long does it take? 

The procedure takes about 30 minutes. 

Does it cause discomfort? 

You will probably experience some period-like cramps during the procedure. These are usually well tolerated and resolve quickly.

Can I try for a pregnancy the cycle in which I have the test?

The contrast agent used is a mixture of air and saline. It is safe to try for a pregnancy in the same cycle as you have had a tubal patency study. 

What happens if fallopian tubes are blocked?

The fallopian tubes carry the egg (produced by the ovary) into the uterus. The egg can be fertilised by a sperm in the fallopian tube, after which it passes into the uterine cavity and implants into the lining of the uterus, resulting in a pregnancy. If the fallopian tubes are blocked even if both the eggs and sperm are normal falling pregnant naturally is unlikely.

With the rapid improvement of in-vitro fertilisation (IVF) most women who have tubal infertility can go on to have the family they desire.  Tubal micro-surgery to correct tubal infertility is technically possible, but generally results in poorer pregnancy rates than IVF.

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