Structural Infertility: What Are the Causes?
Structural Infertility: What Are the Causes?
Getting pregnant and carrying a baby to term involves multiple, often arduous, stages, which can make your fertility journey feel a bit like a marathon. Structural issues within the female reproductive tract can cause a physical barrier to your fertility, much like coming across a 10-foot wall not long after you cross the starting line. Structural infertility can be caused by lots of different things and the management of it will vary for each individual.
Scarring caused by STIs
STIs can come with a wide range of nasty symptoms, but the majority of infected people will have no symptoms at all! This means that many people will have an STI without even knowing it. If left for a long time untreated, STIs such as chlamydia and gonorrhoea can cause pelvic inflammatory disease (PID). PID occurs when the infection spreads from the vagina into the higher reproductive organs, including the womb, ovaries and fallopian tubes. This can cause symptoms such as abdominal pain, abnormal discharge and menstrual bleeding, nausea and pain during sex.
PID can have some serious, long term effects if it is left untreated, including structural infertility1. Structural infertility occurs when the inflammation induced by PID causes scarring, particularly within the fallopian tubes. This causes the tubes to become blocked and prevents the egg from meeting the sperm.
Even if the sperm can wiggle their way through, scarring caused by PID can increase your chances of having an ectopic pregnancy2 (a pregnancy in the wrong place). This happens when the scar tissue in the fallopian tube prevents the fertilised egg from travelling to the womb. Instead, it increases its chances of getting stuck in the fallopian tube and implanting there. This kind of pregnancy is not viable and won’t develop into a baby but can have serious health implications if not treated quickly. Sometimes, surgery is needed to remove the fertilised egg and often the fallopian tube must be removed too. This can mean that you may need IVF treatment to have a baby in the future.
Endometriosis and structural infertility
Endometriosis is a common gynaecological disorder in which cells similar to those which line your womb are found elsewhere in the body. Like the lining of your womb, these cells will bleed and can often cause chronic pain. It can also cause many other symptoms, including structural infertility. This can happen when scar tissue develops in your reproductive organs, causing adhesions and blockages. This can prevent you from getting pregnant or maintaining a pregnancy.
To find out more about endometriosis and its management, check out “Endometriosis Symptoms – Not Just a Painful Period” and “Managing Endometriosis: The Options Post-Diagnosis” in our knowledge centre.
Fibroids and structural infertility
Fibroids are non-cancerous masses of cells that grow in the womb in response to oestrogen. They are common and are found in one in three and are particularly predominant in people of African-Caribbean origin. They are also found more commonly in people overweight, as they have more oestrogen in their bodies.
Fibroids can become large, with some growing up to the size of a watermelon! Although size matters, location can have more of an impact! Not all fibroids will need treating and many won’t even know they have them. If they are causing symptoms or are making it difficult to get pregnant, the number, size and location of the fibroids need to be considered before any action is taken.
Fibroids can either grow on the outside, in the muscular wall or into the cavity of the womb. Those that grow on the outside are called subserosal fibroids. These generally don’t cause any fertility issues, unless they grow to be big. Similarly, fibroids that grow in the muscular wall of the womb (intramural fibroids) can be completely harmless, unless they become large and distort the shape of the uterus. It is the fibroids that grow into the cavity of the womb that cause the most problems, as they don’t have to be very big to start distorting the lining of the womb, which makes it hard for a fertilised egg to implant. These fibroids are called submucosal fibroids.
In addition to disrupting the lining of the womb and its shape, fibroids can also cause infertility by interfering with the movement of the sperm and eggs. This can happen when the fallopian tubes become blocked by fibroid growth, or in rare cases, the cervix becomes obstructed which prevents sperm from swimming into the womb. Fibroids can also interfere later down the line, with large fibroids increasing the risk of preterm birth and miscarriage3.
Congenital changes in shape
Some people are born with a different shaped womb and it is likely they won’t know about it until they have a pelvic examination. Womb alterations come in all different shapes and sizes, with some having connections to only one fallopian tube and others having a section of tissue (septum) splitting the uterus into two! The type and severity of the change will determine its influence on your fertility and management will be dealt with on a case by case basis.
Diagnosing structural infertility
Structural infertility is diagnosed through a pelvic examination, which initially involves a speculum examination and an ultrasound scan. If more information is needed, there are a whole range of additional procedures that can be done to get a better insight into the shape of your womb.
A hysteroscopy is a procedure in which a tiny camera is put through the cervix and into the womb to allow specialists to see inside. This is a really good way to see if anything is altering the shape of the cavity or blocking the fallopian tubes. Alternatively, an MRI scan can be used to see the 3D structure of your reproductive organs. This can be helpful in circumstances where the issues are complex, such as having lots of fibroids.
If it is suspected that your fallopian tubes might be blocked, you may want to have a hysterosalpingogram (HSG). This procedure involves injecting a radioactive dye into your womb, followed by an X-ray to visualise the dye. If everything is as it should be, the dye will flood the cavity of the womb, and travel down the fallopian tubes to the ovaries. It can be seen if there is a blockage as the dye won’t pass through the fallopian tubes and will stay within the cavity. The same technique can also be done with a different dye and an ultrasound scan, which is called hysterosalpingo-contrast-ultrasonography.
A laparoscopy can be used to investigate any structural issues and surgically correct them at the same time! It involves keyhole surgery to insert a small camera into the lower abdomen to examine the womb, fallopian tubes and ovaries. Sometimes a dye is injected through the cervix into the womb to see whether there are any blockages in the fallopian tubes. If it is appropriate, the surgeons can operate immediately after the investigation to try and solve the problem right there and then!
Treatment for structural infertility
Depending on its severity, it may be possible to correct structural infertility with surgery. This is like taking a sledgehammer to that 10-foot wall so you can continue to run! As surgery comes with its risks, it is only considered in circumstances where severe symptoms are being experienced, the condition is becoming detrimental to fertility, and surgery is likely to improve the problem. It is important to remember that surgery is very invasive and sometimes it can cause even more issues than those already being experienced. You can discuss what is right for you with your specialist before any decisions are made.
Experiencing infertility can be extremely challenging and can understandably take its toll on your mental wellbeing. Understanding your own body can help to equip you with the knowledge you need to make the right decisions for your health. At Hertility, we’re here to get you the answers you deserve and support you throughout your journey with our trusted experts. If you are struggling, please reach out to us – we’re always here to help.
1. Wiesenfeld, H.C., Hillier, S.L., Meyn, L.A., Amortegui, A.J. and Sweet, R.L., 2012. Subclinical pelvic inflammatory disease and infertility. Obstetrics & Gynecology, 120(1), pp.37-43.
2. Den Heijer, C.D., Hoebe, C.J., Driessen, J.H., Wolffs, P., Van Den Broek, I.V., Hoenderboom, B.M., Williams, R., De Vries, F. and Dukers-Muijrers, N.H., 2019. Chlamydia trachomatis and the risk of pelvic inflammatory disease, ectopic pregnancy, and female infertility: a retrospective cohort study among primary care patients. Clinical Infectious Diseases, 69(9), pp.1517-1525.
3. Purohit, P. and Vigneswaran, K., 2016. Fibroids and infertility. Current obstetrics and gynecology reports, 5(2), pp.81-88.