Hysterosalpingogram (HSG) is an important test of fertility. It assesses the uterine cavity and determines whether the Fallopian tubes are open.
When I was trying to get pregnant I had one. Like my patients now, I experienced the pain of the process. You call the HSG centre/hospital on the first day of your period. They tell you they have no appointments available this month and to call back with your next menstrual cycle. You eventually get an appointment for the test. At the appointment you change into a hospital gown and go into a procedure room. You lie on the table and the radiologist comes in to the room. They tell you what to expect (all I was really thinking while he was talking was “how much is this going to hurt?”). They put the speculum in the vagina and clamp the cervix. A syringe injects dye through the cervix which causes cramps and (for me) a weird warm feeling in my pelvis. They take a couple of x-rays for which you might have to shift your body around to help them get properly. It hurts a bit (I know some people find it excruciating but most patients report mild/moderate pain for about 2 minutes). That’s it. You head home waiting for the report.
Then a few days later your doctor gets the report. My report read “the Fallopian tubes are patent. There is a large uterine septum.”
A uterine septum results when the uterus does not form properly as a fetus. It is not all that common - only about 3% of all women have a septum but if you look just at women with repeated miscarriages or infertility it is closer to 15%.
Studies indicate that a uterine septum increases your risk of miscarriage and should always be removed in women with 2 or more miscarriages. Septums do more than cause miscarriage though: they decrease the success rate of IVF and increase the risk of preterm birth, fetal growth restriction, malpresentation and placental abruption.
Now, the problem with studies on septums is that they include women with different sizes of septi and different reproductive histories. There are not a lot of great studies out there on septum, honestly. When I was in my fellowship studies at that time only suggested we should be removing septum in women with 2 or more miscarriages. Since then more literature has suggested everyone with a septum should have it removed.
The best available evidence describing the potential impact of a uterine septum on IVF success is derived from a study 289 embryo transfers that were performed before uterine septum surgery and 538 were performed after surgery. IVF outcomes were compared with those of two consecutive embryo transfers in matched women without a septate uterus. They found the septum reduced the chance of success 7 fold. Good evidence that septum should be removed before IVF.
Reference: Tomaževič T, Ban-Frangež H, Virant-Klun I, Verdenik I, Požlep B, Vrtačnik-Bokal E. Septate, subseptate and arcuate uterus decrease pregnancy and live birth rates in IVF/ICSI. Reprod Biomed Online. 2010 Nov;21(5):700-5.
There are no studies that suggest we should be removing septum in women who plan to conceive with intercourse or insemination - they just haven’t been done. Knowing that septum increase the risk of miscarriage and failed IVF and knowing how septi might harm uterine function and implantation is enough for me to recommend all septums - big or small be removed.
I had my septum removed, after failed IUIs, in 2008. I conceived in the cycle immediately after the surgery and gave birth at term to a healthy girl. I then went on to have a few miscarriages but eventually gave birth to 2 more healthy children.
Getting an HSG can be a hassle and the test hurts BUT it is incredibly helpful to understand your uterine anatomy and status of the Fallopian tubes.
Disclaimer: septum, septate, septi, septums - I’ve these words them variably and in some places incorrectly in this text. My autocorrect keeps switching them around!
Reproductive Endocrinology & Infertility