HyCoSy Explained
(Hysterosalpingo-Contrast Sonography)
"A modern ultrasound test used to check whether your fallopian tubes are open—without using X-rays."
What is a HyCoSy?
A HyCoSy (pronounced high-co-see) is a specialised ultrasound scan that checks:
Your uterus (womb)
Your fallopian tubes
Whether your tubes are open or blocked
Instead of using X-rays and dye, a specially trained doctor or sonographer passes a small amount of sterile contrast fluid (and sometimes tiny air bubbles or foam) through the cervix while watching everything in real time using ultrasound.
If the fluid flows through the tubes and spills into the pelvis, the tubes are considered open.
If it doesn't, a blockage may be suspected.
Why is a HyCoSy done?
A HyCoSy is often offered as part of a fertility investigation because it can assess the womb and fallopian tubes in a single appointment.
It may help identify:
Blocked fallopian tubes
Hydrosalpinx (fluid-filled tubes)
Polyps
Fibroids
Congenital abnormalities of the uterus
Adhesions (scar tissue) affecting the uterine cavity
Some clinics prefer HyCoSy over HSG because there is no exposure to radiation.
How is it different from an HSG?
Although both tests check whether the fallopian tubes are open, they work in different ways.
HSG
Uses X-rays.
Uses a contrast dye visible on X-ray.
Images are taken during the procedure.
HyCoSy
Uses ultrasound.
Uses sterile contrast fluid or foam.
Allows the doctor to watch the fluid moving through the tubes in real time.
No radiation is involved.
Both tests can provide excellent information, and the best choice depends on your clinic and your individual circumstances.
What happens during the test?
The procedure is similar to having a cervical smear.
A speculum is gently inserted into the vagina.
A very thin catheter is passed through the cervix.
The speculum is removed.
An internal ultrasound probe is inserted.
The contrast fluid is slowly introduced.
The doctor watches to see whether the fluid passes through the fallopian tubes.
The appointment usually takes around 20–30 minutes.
Does it hurt?
Experiences vary.
Many women describe:
✓ Mild period-like cramps.
Others experience:
✓ Moderate discomfort as the fluid passes through the tubes.
If a tube is blocked, the cramping may be stronger for a short time.
The discomfort usually settles quickly once the procedure is over.
Can a HyCoSy detect hydrosalpinx?
Often, yes.
A hydrosalpinx may appear as a swollen, fluid-filled fallopian tube on the ultrasound.
The movement of the contrast fluid can also help doctors assess whether the tube is functioning normally.
Sometimes additional investigations, such as laparoscopy, may still be recommended.
Is a HyCoSy accurate?
Yes.
For assessing whether the fallopian tubes are open, HyCoSy is considered highly accurate and compares well with HSG in many studies.
However, like all investigations, it has limitations.
Sometimes muscle spasm around the tube can temporarily stop the flow of fluid, making a tube appear blocked when it is actually open.
If results are uncertain, further testing may be advised.
Can a HyCoSy improve fertility?
Possibly.
As with HSG, there is some evidence that gently flushing the tubes during the procedure may increase the chance of pregnancy for a short period afterwards in some women.
Researchers are still studying exactly why this happens.
The main purpose of the test, however, is diagnosis rather than treatment.
Questions you may wish to ask your doctor
Were both tubes open?
Did the contrast spill freely from both tubes?
Was there any sign of hydrosalpinx?
Were there any abnormalities in my uterus?
Do I need further investigations?
Would laparoscopy provide additional information?
A gentle reminder
A HyCoSy provides valuable information about the womb and fallopian tubes, but it cannot diagnose every cause of infertility.
A normal HyCoSy does not rule out:
Endometriosis
Ovulation problems
Egg quality issues
Sperm factors
Some forms of pelvic adhesions
Sometimes further investigations are still needed to complete the picture.
Did you know?
Because HyCoSy uses ultrasound instead of X-rays, many fertility specialists now use it as their first-choice test for checking the fallopian tubes.
It can often answer the same important questions while avoiding radiation exposure.
Georgina's Note ❤️
When you're first navigating infertility, it's easy to feel overwhelmed by all the different test names.
HSG. HyCoSy. SIS. Laparoscopy.
They can sound frightening, but each one is simply another way of gathering pieces of the puzzle.
Understanding what each test is looking for can make appointments feel a little less daunting and help you ask informed questions about your own care.
Knowledge doesn't remove the uncertainty—but it can replace some of the fear.