A tubal obstruction is when your fallopian tubes are blocked. Sperm travels through your tubes to reach the egg, and the egg uses your tubes to reach your uterus. So it can cause major challenges to fertility if this road is blocked. Causes of blocked tubes include endometriosis, chlamydia or other STDs, pelvic surgeries, or traumas like a ruptured appendix, car accident or bowel diseases like Crohn’s.
Tubal blockage is relatively common, so you might expect we’d have tests to clearly identify it. Unfortunately, we don’t. Imaging and scans are imperfect. To make it even more challenging, your tubes are muscular and can open and close on their own! You might have a perfectly fine tube that appears in imaging as being “blocked” – just because it closed itself.
You can also be diagnosed with a “functional tubal obstruction”. That means your tubes aren’t fully obstructed, but still aren’t working properly. This is actually far more common than truly blocked tubes! It’s caused by the same issues – endometriosis, surgery, etc – and usually the problem is located at your fimbria (the “fingered” ends of the tubes).
Your fimbria “catch” the eggs that your ovary releases. It’s a delicate dance between your fimbria, ovary and follicle. So if the fimbria are simply clogged up, it’s more likely that the egg will fall into your pelvis instead of landing in your tube to await fertilization.
The lining of a tube have problems as well. A fallopian tube isn’t just a “pipe”. It’s actually a muscular structure filled with cilia, little hair-like structures. The delicate cilia help propel sperm up the tubes from the uterus, and eggs back down into the uterus. Even small abnormalities or scar tissue within the tube can make it hard to conduct the sperm or eggs towards their destinations.
Finally, there’s a relatively rare diagnosis called “sinus isthmus mudosa”. It means you were born with functionally obstructed fallopian tubes.
A hystosalpingogram (HSG) is an x-ray test. We inject a dye into your uterus, and watch it flow through your tubes in the x-ray.
However, if your tubes have decided to clamp down at the moment of the test, one or both will appear obstructed even though they aren’t! Another problem is that if one tube is particularly open, all the fluid will gravitate towards that tube, and the other tube won’t be as visible. As doctors, it’s hard for us to tell whether the tube is blocked or just invisible from the image.
Finally, the HSG can’t detect problems with your fibria or scar tissue on the outside of the tubes. If one of those is the problem, the HSG can’t help us.
An alternative to the HSG is a sonohystogram. It’s basically the same test, but it uses an ultrasound and water instead of an x-ray and dye. Unfortunately, it’s no good at identifying fimbria or outer-tube issues either.
Our best test is definitely a laparoscopy. However, it’s done much less often nowadays. That’s because it’s extremely invasive, won’t necessarily give us the information we need, and is rarely able to fix the problem.
So although many doctors would love to know whether your tubes are fully functional, very few doctors believe it’s appropriate to do a diagnostic laparoscopy during the first stages of your fertility treatment journey.
Surgery is rarely able to fix blocked tubes. That said, there are exceptions, and we strongly recommending talking about it with your doctor.
We often suggest tubal cannulation and an HSG. That means we’ll push a catheter up through your cervix into your uterus, and ideally right into your fallopian tube. That can sometimes unclog whatever was in the way.
Neat fact: sometimes a woman’s blockage is so minor that the fluid used in her HSG or sonohystogram can help to unclog her tubes! Although doctors still aren’t sure what causes these minor blockages, it seems more common in women with chronically low estrogen (such as woman who are underweight, or have a low ovarian reserve or reduced egg quality).
There’s a small but real percentage of cases in which the woman gets pregnant in the cycle or two after a tube check, which is why we believe this test can be therapeutic as well as informative.
However, the most successful treatment for tubal dysfunction is to simply use IVF instead. It’s the ultimate way of bypassing a blocked tube.