HyCoSy (Tubal Patency Ultrasound): How Clinics Assess Your Fallopian Tubes
If you’ve been referred for a HyCoSy or are considering booking one, you might be wondering what the test involves and whether it’s right for you. This guide outlines when it’s used, how it’s done, and what to expect before and after the procedure.
Author
Tassia O’Callaghan
Reviewed by
Kayleigh Hartigan
16 min read
Updated 21st August 2025
Spotlight:
- HyCoSy is a specialist ultrasound scan that checks if your fallopian tubes are open and your uterus is structurally healthy.
- It’s a common part of fertility investigations, especially when other test results are inconclusive or before starting IUI or IVF.
- The procedure takes around 20 minutes and is usually done in a fertility clinic on an outpatient basis — no sedation or hospital stay needed.
- HyCoSy is generally well tolerated, with many describing it as mildly uncomfortable rather than painful.
- You may be able to get a HyCoSy through the NHS, but access depends on your location and local Integrated Care Board (ICB).
What is a HyCoSy?
HyCoSy stands for Hysterosalpingo-Contrast Sonography. It’s a specialised type of ultrasound used to check whether your fallopian tubes are open (patent) and if your womb (uterus) looks healthy. [1,2,3]
During the test, a contrast dye is gently passed through your cervix to outline the womb and fallopian tubes. This dye is specifically designed for this kind of scan — it’s safe, doesn’t affect your fertility, and simply makes the structures easier to see on an internal (transvaginal) ultrasound. [4]
Because fallopian tubes are too fine to show up on an ultrasound without dye, HyCoSy offers a clearer picture of how open and functional they are. It can also pick up any irregularities in the womb lining (endometrium) that might impact implantation.
HyCoSy is usually carried out by a sonographer with specialist training in fertility imaging. It’s done on an outpatient basis, whether you have it carried out at a fertility clinic or hospital — meaning no hospital stay, no sedation, and you can usually go home the same day. [5]
Does a HyCoSy flush your tubes?
While the main purpose of a HyCoSy is to check whether your fallopian tubes are open, the process of gently passing contrast through them might offer more than just a diagnosis. Some research suggests that the test may have a therapeutic effect — by flushing out small blockages, debris or mucus that could be interfering with the natural movement of sperm, eggs, or a fertilised embryo.
In fact, one study found that around 1 in 5 people conceived naturally within six months of having a HyCoSy, with nearly half of those pregnancies happening in the first 30 days. While more research is needed, this “flushing effect” could help explain why some people experience a short-term boost in fertility after the test. [6]
Who is a HyCoSy test for?
A HyCoSy test is typically recommended for those assigned female at birth who are undergoing fertility investigations, but it’s not a blanket test for everyone who’s been trying to conceive for 6+ months. It’s used to check whether the fallopian tubes are open or blocked, and can help identify issues that may be preventing pregnancy — but timing, symptoms, and medical history matter.
A HyCoSy (or a similar test like an HSG) is usually offered after initial fertility tests, such as hormone testing and semen analysis, have been done — and if they haven’t uncovered a clear cause of infertility. This is because it’s more invasive and not always necessary for everyone. [7,8]
You may be offered a HyCoSy if:
- You’ve been trying to conceive for over 12 months (or 6 months if you’re over 36) and initial tests haven’t revealed a cause.
- You’re planning fertility treatment like IUI or IVF.
- You have a history of conditions that could affect the fallopian tubes — such as pelvic inflammatory disease (PID), endometriosis, an ectopic pregnancy, or previous abdominal or pelvic surgery.
- You’re experiencing irregular bleeding or symptoms that may suggest uterine or tubal abnormalities.
Your clinician may also recommend a HyCoSy to rule out structural abnormalities that could impact fertility, or to help determine the most appropriate next steps in your treatment pathway.
On the other hand, a HyCoSy might not be recommended if:
- You already have a known reason for infertility (such as very low ovarian reserve or absent ovulation).
- You’re planning to move straight to IVF, where fallopian tube function isn’t always a deciding factor.
- Your clinical team suggests a different type of scan, such as an HSG (hysterosalpingogram) or laparoscopy, based on your symptoms or history.
Fertility Test: What It Is, What It Costs, What It Can Tell You
From hormone checks to sperm analysis, we break down the most common fertility tests — plus where to get tested and how to understand your results.
How accurate is the HyCoSy test?
HyCoSy is a highly accurate way to assess tubal patency and the structure of the uterus, with studies showing it correctly identifies open or blocked tubes in over 90% of cases. In comparisons with laparoscopy and HSG, it has demonstrated sensitivity rates of 85–88% and specificity up to 95–100%. [9,10]
While no test is perfect, HyCoSy results are generally reliable. Around 5% of scans may be inconclusive due to factors like cervical stenosis, scarring, or fibroids, in which case further investigation might be needed. [1]
Can HyCoSy be wrong?
While rare, false positives and false negatives can happen — especially if the test causes a temporary spasm in the fallopian tube, which can look like a blockage. Other factors, such as a narrowed cervix, uterine scarring, or fibroids, can also affect the accuracy of the scan. If your results are unclear or unexpected, your fertility specialist may recommend further testing (like an HSG or laparoscopy) to double-check. [11]
How is a HyCoSy done?
The test begins with a transvaginal (internal) ultrasound to assess your uterus and ovaries. This involves a small probe being gently inserted into the vagina to capture clear images.
Next, a speculum is inserted — similar to what you might experience during a cervical smear — to allow access to the cervix. A thin plastic catheter is then passed through the cervix into the womb. Once it’s in place, a contrast dye is slowly flushed through the catheter while a second internal ultrasound tracks the flow. [1,2,3]
If your fallopian tubes are open, the dye will usually be seen passing through them and into the pelvic cavity. If it doesn’t appear, this may suggest a blockage, but further testing is sometimes needed to confirm. [4]
If you want to bring someone with you, you can — it’s important that you’re comfortable during the procedure.
How much time does HyCoSy take?
The procedure itself usually takes around 20 minutes, though this can vary slightly depending on individual anatomy and how easily the catheter is inserted. In total, you can expect to be in the clinic for about 30 to 60 minutes to allow time for a pre-procedural chat with the sonographer, the procedure itself, and time for any necessary “clean-up” afterwards — the dye will typically leak out for a few hours once the procedure is done, so it’s recommended to wear a sanitary pad after. [2]
Can I ask my GP for a HyCoSy?
Sometimes — it depends on your circumstances and location. Some GPs may refer you for a HyCoSy on the NHS after a period of trying to conceive. However, access can be limited and waiting times vary, depending on your ICB (Integrated Care Board).
ICBs are regional NHS bodies responsible for planning healthcare services in your area — including fertility care. Each one sets its own eligibility criteria and funding priorities, which means access to tests like HyCoSy can differ from one postcode to another. Some areas may fund this investigation early in the fertility pathway, while others may not offer it until later, or only alongside other treatments.
If you want faster results or don’t meet NHS criteria, you can book a HyCoSy privately. You can find a clinic that offers this service using our clinic search or our Clinic Match tool.
Find the right clinic for you
Choosing a clinic is one of the biggest decisions you’ll make. We’ll find the best options for you and arrange your pre-treatment tests, empowering you from this point onwards.
How much does HyCoSy cost?
In most UK-based fertility clinics, HyCoSy is billed as a separate diagnostic procedure, rather than being included in standard fertility assessments. Prices typically range from £408 to £800, with the average cost around £550.
Some clinics may bundle it into a broader package — such as an advanced fertility MOT or treatment planning pathway — but this isn’t standard practice. If you’re comparing clinics, it’s worth double-checking whether HyCoSy is included or needs to be booked (and paid for) separately.
Also keep in mind that if HyCoSy is recommended as part of NHS-funded fertility care, it may be covered — but this depends on your eligibility and local NHS criteria.
When should a HyCoSy be done?
A HyCoSy is usually carried out between days 6 and 12 of your menstrual cycle, after your period has ended but before ovulation. This timing ensures a clear view of the womb and fallopian tubes while minimising any risk to an early pregnancy. [2]
If you’re having the test through the NHS, it’s often recommended to contact your GP or local referral team on the first full day of bleeding to request a booking within that window. If you’re going private, most fertility clinics will ask you to do the same — reaching out on day 1 of your cycle so they can schedule your scan at the appropriate time. [1]
What to do before a HyCoSy
Preparing properly for your HyCoSy can help make the process smoother and ensure your results are as accurate as possible. Your clinic should give you specific guidance, but here’s what’s commonly recommended:
- Avoid pregnancy in the lead-up to your scan: Use condoms or avoid intercourse altogether from the start of your cycle. This is because the procedure can potentially “flush out” an early pregnancy. [2]
- Stop fertility medication like Clomid: You’ll usually be asked to pause this for the month of your HyCoSy, as it can interfere with the timing or safety of the scan. [2]
- Take pain relief one hour before your appointment: Unless told otherwise, you can take 400mg of ibuprofen or 1g of paracetamol to help with any cramping. [2,12,13]
- Eat and drink normally on the day: There’s no need to fast beforehand, but some clinics recommend a low-fibre diet or gentle laxatives the day before to improve scan visibility.
- Get a chlamydia screening: This should be done before your appointment, as undiagnosed infection can be pushed further into the reproductive tract during the procedure. You can book this with your GP or arrange it privately — just make sure the results are back in time. If not, your clinic may prescribe antibiotics instead. [5]
- Take a pregnancy test: Some clinics will ask you to take a test at home that morning to ensure you’re not pregnant; others will do it on-site. If testing at the clinic, arrive with a full bladder. If testing at home, an empty bladder is usually preferred for the scan itself. [2]
- Wear something comfortable and bring a sanitary pad: Light spotting and/or the dye leaking out afterwards is common. [14]
If you’re feeling nervous or unsure about any part of the process — especially around medication, consent, or logistics — don’t hesitate to contact your clinic for clarification.
What happens after a HyCoSy?
Most people feel well enough to return to their usual activities straight after the procedure. You might notice some light pink or white discharge for a day or two, which is completely normal. It’s also safe to have unprotected sex once the scan is complete, unless advised otherwise by your clinic. [2]
Your GP or fertility specialist will usually arrange a follow-up appointment within a few days to a week to go over your results and discuss any recommended next steps in your care.
What not to do after a HyCoSy
Avoid using tampons for the first few days following your HyCoSy, as this can reduce the risk of introducing infection — you can go back to using them as normal with your next period. If you’ve been prescribed antibiotics (often due to pending or positive chlamydia screening results), make sure you take the full course as directed. Skipping or delaying them can increase the risk of complications. [15]
How long do HyCoSy results take?
In many cases, your doctor or sonographer will give you a summary immediately after the test. A full report is usually ready within a few days and can be discussed at your next appointment.
How do you feel after HyCoSy?
It varies — some people feel fine, while others describe mild cramps, spotting, or fatigue. For most, the discomfort settles within a few hours. If you experience heavy bleeding, fever or ongoing pain, contact your clinic.
Is it easier to get pregnant after HyCoSy?
Some people do conceive naturally in the weeks or months following a HyCoSy, and research suggests there may be a short-term fertility benefit linked to what’s known as the “tubal flushing” effect. This refers to the idea that flushing contrast dye through the fallopian tubes may help clear minor debris or mucus, potentially improving the passage of sperm or eggs. [16]
Several studies — including case reports and observational trials — have shown higher rates of spontaneous pregnancy in the first 30 days after the test, particularly in people with unexplained infertility. However, larger randomised controlled trials have found only a small and statistically insignificant difference compared to those who didn’t have the procedure. [16,17,18]
While HyCoSy is primarily a diagnostic test, some people may experience a temporary increase in their chances of conceiving naturally. But this effect isn’t guaranteed, and it may not apply to everyone.
What is the success rate after HyCoSy?
While HyCoSy itself isn’t a treatment, studies show that pregnancy rates may rise slightly afterwards, particularly for people with unexplained infertility. Some studies suggest that around 19–30% of people conceive naturally within six months of having a HyCoSy, with many of those pregnancies occurring in the first month. This may be linked to a temporary “tubal flushing” effect, where the contrast medium clears minor blockages. While promising, not all research confirms a significant fertility boost — so HyCoSy is best seen as a diagnostic tool, with a possible short-term benefit for some. [16,17,19]
Is a HyCoSy worth it?
If you’re trying to understand your fertility or preparing for treatment, a HyCoSy is often a useful step. It gives a clearer picture of your reproductive anatomy and may help guide next steps — whether that’s reassurance, a change in treatment plan, or further investigation.
HyCoSy FAQs
What is the difference between HSG and HyCoSy?
HSG uses X-rays and an iodine-based dye to assess the uterus and fallopian tubes, while HyCoSy uses ultrasound and a fluid-based contrast agent. Both are effective, but HyCoSy is generally better tolerated, avoids radiation, and can also assess the ovaries during the same scan. HSG provides clear static images and a permanent record, but it tends to be more uncomfortable and carries a slightly higher risk of side effects. Many clinics now prefer HyCoSy for its safety, comfort, and convenience. [2,20,21,22]
Is HyCoSy necessary for IVF?
HyCoSy isn’t always required before starting IVF, but it’s sometimes recommended as part of the initial fertility workup — especially if the reason for not conceiving isn’t clear after tests like AMH (Anti-Mullerian Hormone), AFC (Antral Follicle Count), and semen analysis. If the scan shows that one or both fallopian tubes are blocked or damaged, IVF may be advised as the most effective next step. Some clinics include HyCoSy routinely to rule out tubal factors before proceeding with treatment.
Can HyCoSy see endometriosis?
No — HyCoSy cannot detect endometriosis. While it can assess whether your fallopian tubes are open, it can’t identify scar tissue or adhesions around the tubes, which are common in endometriosis. If endometriosis is suspected, a laparoscopy is usually needed to confirm the diagnosis and assess its severity. [1]
Do you need a full bladder for HyCoSy?
It depends on your clinic’s protocol. Some ask you to arrive with an empty bladder to improve scan visibility, especially if you’ve already taken a pregnancy test at home. Others may require a full bladder for an on-site pregnancy test before the procedure. Your clinic should confirm their specific instructions in advance — and if you’re unsure, it’s always okay to ask.
Are you awake for HyCoSy?
Yes, you’ll be awake for the entire procedure. You’ll be lying on your back, and no anaesthesia is needed, as the test is usually quick and well tolerated. [3]
How painful is the HyCoSy test?
Most people describe HyCoSy as more uncomfortable than painful — often comparing it to period-like cramps or a smear test with added pressure. The sensation usually passes quickly, and taking pain relief about an hour before can help ease any discomfort. While it’s not exactly pleasant, it’s generally short-lived and manageable. [2,15]
Do you bleed after HyCoSy?
Some light bleeding or spotting is common after a HyCoSy, usually caused by the catheter passing through the cervix. It’s typically mild and should settle within 24 hours. You may also notice some sticky, odourless discharge as your body expels the contrast agent — both are completely normal. [15]
Can I drive after a HyCoSy?
You can usually drive after a HyCoSy, but it’s best to wait at least an hour before getting behind the wheel. Some people feel lightheaded or have light cramping afterwards, so if possible, arrange for someone to accompany you or take you home, just in case you don’t feel up to driving straight away. [23]
Can I go to work after HyCoSy?
You may be able to return to work after the procedure, but some people prefer to rest for the remainder of the day. It’s worth keeping your plans flexible, as you might experience mild discomfort or fatigue following the scan. [23]
Do I need antibiotics after HyCoSy?
Not everyone needs antibiotics after a HyCoSy, but they may be prescribed in certain situations. If your chlamydia screening results aren’t available in time — or come back positive — your clinic or GP will likely prescribe you antibiotics to take as a precaution. There’s also a small risk of developing a uterine infection after the procedure, so if you experience symptoms like a high temperature, body aches, or unusual discharge in the days following your scan, it’s important to contact your GP promptly for treatment. [14]
Sources
1. https://abuhb.nhs.wales/files/patient-information-leaflets1/womens-health/hysterocontrastsonography-hycosy-the-procedure-explained-piu1595-1-pdf/
2. https://www.buckshealthcare.nhs.uk/pifs/hystero-contrast-sonography-hycosy/
3. https://www.ouh.nhs.uk/media/ghhpjq3p/102777hycosy.pdf
4. https://www.hey.nhs.uk/patient-leaflet/hysterosalpingo-contrast-sonography-hycosy-pre-test-information/
5. https://www.leedsth.nhs.uk/patients/resources/hysterosalpingo-contrast-sonography-hycosy/
6. https://pubmed.ncbi.nlm.nih.gov/23346526/
7. https://www.hfea.gov.uk/choose-a-clinic/preparing-for-your-clinic-appointment/
8. https://www.hfea.gov.uk/about-us/a-z-fertility-glossary/
9. https://www.jmig.org/article/S1553-4650(10)00671-0/fulltext
10. https://pubmed.ncbi.nlm.nih.gov/25597884/
11. https://www.leedsth.nhs.uk/patients/resources/hysterosalpingography-hsg/
12. https://radiology.ucsf.edu/patient-care/prepare/hysterosalpingo-contrast-sonography
13. https://www.uhcw.nhs.uk/download/clientfiles/files/hycosy (GEN-PI-000005V16).pdf
14. https://www.ulh.nhs.uk/wp-content/uploads/2015/06/Hysterosalpingo-Contrast-Sonography-Aftercare-leaflet.pdf
15. https://www.hey.nhs.uk/patient-leaflet/hysterosalpingo-contrast-sonography-hycosy-aftercare/
16. https://onlinelibrary.wiley.com/doi/10.1155/2024/7774854
17. https://academic.oup.com/humrep/article-abstract/24/5/1075/711185
18. https://bmcpregnancychildbirth.biomedcentral.com/articles/10.1186/s12884-020-03315-x
19. https://pmc.ncbi.nlm.nih.gov/articles/PMC10187797/
20. https://pmc.ncbi.nlm.nih.gov/articles/PMC11218854/
21. https://academic.oup.com/humrep/article-abstract/26/5/967/674503
22. https://www.nbt.nhs.uk/our-services/a-z-services/imaging-x-ray/imaging-patient-information/hysterosalpingogram-hsg
23. https://so.merseywestlancs.nhs.uk/media/.leaflets/681a122f257403.04491852.pdf