Fertility Testing: The Hysterosalpingogram (HSG)
Hello everyone and welcome back to another episode. I'm hoping that you're liking the content. The way I structured this was to take you through the journey of a patient. So starting with introducing myself, the new patient consult talking about the menstrual cycle is kind of one of those foundational things that we need to know and then taking you through testing and then we'll follow up with treatment afterwards.
Today we're going to be talking about Tubal Assessment. Specifically. I want to talk about the HSG. HSG is an acronym. It is short for hysterosalpingogram and in Greek, that is the study of the Fallopian tubes, which is the salpingo part, and the uterus which is the histero part.
So the hysterosalpingogram has been around for a long time. It is the standard of care when it comes to tubal assessment, and basically what we're looking for is ‘Are those tubes open or closed?’ It also gives us the opportunity to assess the inside of the uterus. If you remember the uterus is a virtual space, it's collapsed on itself when we inject saline that allows us to open up the cavity and look inside and make sure there's no polyps or fibroids inside the cavity. But really we're also looking at the Fallopian tubes. We want to make sure that those are open, that there's no issues with them, and that study has been around for a while.
Typically that is going to be performed by a fertility clinic or by a radiology center and part of that variation depends on what state you're practicing in because different states have different laws surrounding radiation.
When you talk about fertility testing and you talk about the HSG typically what happens is the patient will call on cycle day 1 of her menses. So remember cycle day one is first day of full flow and what we'll do is we'll go ahead and schedule that patient. Typically we schedule for cycles days 6-10 or 6-12 depending on the center. The idea essentially is that you want the patient to have stopped bleeding, but then you want her to not have ovulated yet. So that's the sweet spot that we're trying to get the patient in now. If the patient is on suppression, let's say she's taking birth control pills for any reason, the HSG can be done at any time.
So when you arrive at the center, there's typically a questionnaire just asking about medical conditions, allergies, making sure we're not going to expose you to any unnecessary risk. We then have the patient change into a gown, she would sit on the x-ray table and she is put in pelvic position or gynecological position whichever term you prefer, and we insert a speculum so up until that point, what you feel or what you experience is very much like a pap smear appointment.
The next step is to insert a catheter. Typically the catheter is very small, but it has a balloon on the end of it, and so what happens is if you think of the cervix like a tube, there's an outer opening that connects with the vagina. There's an inner opening that connects with the uterus, and the balloon is inserted through the cervical canal and inflated so that it seals off that canal, so that when they're injecting dye, it doesn't backflow right back towards them into the vaginal vault. We insert the catheter, we inflate the balloon, and then we start slowly injecting dye.
As we're injecting dye we are taking x-ray pictures, and those x-ray pictures are meant to light up the dye, hopefully showing us a normal uterus. If we see a normal uterus typically what we see is an inverted triangle, so that would be a normal uterus, and then we typically see two open Fallopian tubes. Those Fallopian tubes tend to look like a hair strand or a spaghetti noodle on the x-ray. They're very, very small, very thin, and then you see at the end this fluid hopefully should be spilling freely into the pelvis.
The whole exam is not long, it takes about 10-15 minutes but is quite uncomfortable. The contrast is quite irritating to the pelvis, so most patients will report varying levels of discomfort when it comes to the HSG. Most centers will recommend that you take ibuprofen one hour before the procedure. Ibuprofen is bought over the counter typically in 200-milligram tablets so you can take 200. You can take 400. You can take 600 even up to 800 milligrams one hour before the procedure. Just to help with that pelvic cramping and sort of that pain sensation that comes with the injection of dye.
Some centers may also ask that you take an antibiotic the day before, the day of and the day after the procedure. The idea is that if there is an abnormality found they would potentially be protecting you from that infection spilling into the pelvis.
The total exam takes about 15 minutes. If you can take the rest of the day off, that's wonderful. If you cannot just make sure to have Tylenol on hand for after the procedure because you've taken the ibuprofen, it'll be a little while before you can take it again. But you can definitely take Tylenol after the procedure to help ameliorate some of that cramping and discomfort.
Most patients do report varying levels of vaginal bleeding maybe some discharge from the dye after the procedure. Typically that should improve little by little every day. So if you're a week out and you're still having pretty significant pain, that is definitely not normal and you definitely want to talk to the physician that did the study. But most patients will have varying levels of discomfort, and that's going to resolve a little bit differently for everyone, as long as it's continuing to get better then we're not worried. So that would be the one thing that I would share with you guys.
Let's talk about results. So when you talk about results, the benefit of the HSG is its negative predictive value. The negative predictive value is quite high over 90 percent, which means that if you have a normal exam, then it's very reassuring that the inside of your uterus and both Fallopian tubes are probably open and clear. So that's the good news.
However, if an abnormality is found the positive predictive value of this test (what is the likelihood that the abnormality is actually an abnormality?) It is actually pretty low. It's somewhere in the neighborhood of like 35 to 40 percent for the positive predictive value. So what I always tell patients is that if there's an abnormality found, baseline, additional testing needs to be done. Whether that's a repeat HSG, whether that's any sort of other testing, or whether that is a laparoscopy which would be a surgical procedure to actually look at the tubes directly, that's considered the gold standard. But additional testing needs to be done.
Generally speaking, if there is proximal occlusion, so your tube never showed up to the party, it never filled, it never spilled, most of the time, not always, but most of the time that tends to be a clamping down of that smooth muscle in response to the dye as an irritant. So actually the tube is okay, but it's clamping down in response to the dye. So we have to call it blocked on the report, but it may not necessarily be blocked. If the tube fills and is blocked at the end, what we call a distal occlusion, that tends to be higher likelihood for to be true pathology, and if it does that, so if it's fills but it's blocked and then it's dilated and damaged, so think spaghetti noodle is normal, think sausage or hot dog is abnormal. So if the tube is dilated and damaged and not spilling, then again the likelihood of true pathology is much, much higher, and that is something we call a hydrosalpinx or a tube full of fluid.
Now a third scenario is that the tube may fill and spill, but that fluid gets caught outside of the tube. It's called a loculation. The fluid does not move freely in the pelvis afterwards. If that's the case, you may have scar tissue inside the pelvis that is preventing that fluid from moving freely. That could be due to several things, previous infection, endometriosis, previous surgery. There's several risk factors for that. So if there is an abnormality found on your HSG, you definitely want to make sure to speak with your physician about exactly what abnormality was found and what is the follow-up testing or what is the follow-up evaluation recommended to move forward before you actually make final decisions. Now if the decision is to move forward with surgery, at the time of surgery, once the diagnosis is made, the surgeon will have talked to you ahead of time whether or not you guys are going to remove the tube if it's abnormal, if you're going to leave it in place, or what are you going to do so they'll talk to you both about confirming the findings but also managing those findings if they are found to be true.
I hope this has been helpful. So when you're getting your fertility evaluation and they talk to you about an HSG, this is what it is. It's an evaluation of the uterus and Fallopian tubes, it's an x-ray study. It's typically done cycles day six through twelve, and hopefully this is giving you all the details on what to expect and how to move forward based on the results found. Next week, we will finalize talking about the semen analysis because we don't want the guys to feel left out before we jump into treatment. Talk to you soon. Bye bye now.
*This content is intended solely for educational purposes and is not to be construed as medical advice. For personalized recommendations concerning your specific healthcare needs, kindly consult with your healthcare provider.
