Tests used to identify tubal patency
Blocked tubes can happen for several different reasons, but no matter the cause, your doctor will diagnose it with a test called a hysterosalpingogram.
Tubal patency is determined by an x-ray test called a hystero-(uterus)salpingo-(fallopian tube)graphy (HSG). HSG is a standard radiological imaging study that is used to determine if the fallopian tubes are open and free of disease.
It is usually done in the first 10 days of the menstrual cycle. Sometimes the tubes will appear to be blocked on the HSG when they are actually open.
The timing of the HSG study during the menstrual cycle, or the use of hormonal contraception may make a difference in whether the tubes appear blocked on the HSG when they are actually patent.
What is involved in a HSG test?
A hysterosalpingogram, is a special kind of x-ray that involves administering an iodine dye via the cervix, into the uterus and fallopian tubes, while a transvaginal ultrasound (TVUS) is performed.
This allows the technician to see the fluid being injected and assess whether or not it is freely passing through the fallopian tubes. If there is a blockage in any part of one of the fallopian tubes, the dye will struggle to flow around it.
This will be seen on the ultrasound and allows the technician to identify the location of the obstruction.The test is intended to check the general uterine shape and to see if the fallopian tubes are clear.