Endometriosis and Fertility

What is Endometriosis?
Endometriosis is a common, chronic disease which may be suspected in women who experience infertility and/or pelvic pain. There is an increasing public awareness of its effect on fertility and this is important as there are effective treatment strategies to help improve a couple’s fertility and a woman’s pelvic pain symptoms due to endometriosis.

Medically speaking, Endometriosis is defined as where the glandular lining of the womb or the uterus (also called the endometrium) is found outside the uterus. It is commonly seen in the lining of the abdomen and pelvis (called the peritoneum) but can be found anywhere in the body.

If we suspect a couple’s infertility is due to endometriosis, treatment strategies to improve infertility often involves surgery (to excise or resect the endometriosis) and/or assisted conception [Ovulation Induction + Intra-Uterine Insemination (OI/IUI) and In Vitro Fertilisation (IVF)].

How common is endometriosis?
Endometriosis is a common condition. Studies have shown that in the general population, about 5-10% of women (up to 1 in 10 women) are affected by endometriosis, with symptoms typically presenting in women of child-bearing age (ie, from late teenage years the to mid forties).

In patients having difficulty falling pregnant, endometriosis is even more common, with up to 50% of women found to have endometriosis as a contributing cause of their infertility.

Put simply, if a couple is experiencing difficulties trying to conceive, they have a 1 in 2 chance of having endometriosis contributing to their infertility, and higher chances still if the female partner experiences pelvic pain as well.

What causes endometriosis?
The exact cause is actually unknown, but there are several theories that help explain why some women get endometriosis and some don’t.

Probably the simplest explanation is that every month when a woman experiences menstruation (where the endometrial cells are shed), some of the endometrial cells make their way (in a retrograde fashion) back through the fallopian tubes in the abdominal and pelvic cavity.

In women who are susceptible, these endometrial cells seed and grow on the lining of the pelvis (the peritoneum). This helps explain why endometriosis is most commonly found in the dependent parts of the abdomen (ie, the pelvis) and why it is a major cause of infertility and pelvic pain, but it doesn’t fully explain why sometimes we sometimes find endometriosis in other parts of the body including the lung and joint cavities.

How does it impact on a couple’s fertility?
In couples experiencing infertility, endometriosis is common, with up to 50% of the female partners may have endometriosis. In women with endometriosis, the monthly chance of conceiving can be reduced by at least to 50% (or even more) of what is normally expected (from 15-20% per month to 2-10% per month).

The impact of endometriosis on infertility is dependent on the severity of the endometriosis. The stage of the endometriosis correlates to the degree of infertility, but not to pelvic pain symptoms.

It may be difficult to imagine how endometriosis in the pelvis, which is nowhere near the ovaries or fallopian tubes, causes infertility. A simple explanation is that the endometriosis cells alters the hormones and immune factors in the pelvis which is toxic to the eggs. This helps explain why we commonly see a reduction in egg quantity and quality in women with endometriosis. These altered hormones and immune factors can also lead to decreased motility in the fallopian tubes and reduce the receptivity of the endometrium to allow an embryo to implant.

As endometriosis becomes more severe, it can cause significant anatomical distortion by pelvic adhesions and endometriomas (ovarian cysts caused by endometriosis) in addition to hormonal and immune factors.

Altogether, endometriosis provides an unfriendly reproductive environment that affects the quality/quantity of eggs and makes it more difficult for an embryo to implant successfully into the uterus.

What are other symptoms of endometriosis that a woman should look out for?

In addition to infertility, endometriosis causes a range of other symptoms including pelvic pain, pelvic mass or it can be silent or asymptomatic.

Pelvic Pain – To help explain the pelvic pain, each month during menstruation, the endometriosis cells also bleed (as they originate from the same type of endometrial cells), causing painful periods.

Over time, these cells cause scarring in the pelvic cavity – if it affects the ligaments near the cervix, it can cause pain during sex, if it affects the rectum it can cause pain during bowel motions and overall can lead to chronic pelvic pain in the long term.

Pelvic mass – Endometriomas can present as pelvic masses which have a significant impact on egg quality, ovarian reserve and infertility.

Asymptomatic – Women who do not experience pelvic pain but are having difficulty conceiving should raise suspicion of occult endometriosis.

How is the diagnosis made?
Endometriosis may be suspected by a woman’s symptoms and findings on different tests, but the only way to diagnose endometriosis definitively is to send a specimen to the pathologist to look under the microscope. Even if a pelvic ultrasound and blood tests are normal, this does not exclude endometriosis.

Currently, Laparoscopic Surgery (Key Hole Surgery) is the gold standard for both diagnosis and surgical treatment of endometriosis. At the time of Laparoscopic Surgery, we classify the endometriosis to assess its severity. The advantage of Laparoscopic Surgery is that we can treat the endometriosis by excising the endometriosis at the same time.

Are there any effective treatments available to help improve a couple’s fertility?
Endometriosis is a common chronic disease with no cure. At this stage, all the treatments aim to help improve the symptoms that endometriosis is causing and stop it from coming back.

The exciting news is that there are effective treatments available to help improve a couple’s fertility and maximise their chance of having a baby.

Treatments for endometriosis can be summarised into 3 main categories – medical treatments, surgery and assisted conception which includes IVF.

For medical therapies, most of them are hormonal and contraceptive. They are very effective in managing pelvic pain symptoms caused by endometriosis, but as they are generally contraceptive, and thus not very useful in helping a couple fall pregnant.

Laparoscopic Surgery remains the gold standard for both diagnosis and surgical treatment of endometriosis. Medical studies suggest that even resecting minimal/mild endometriosis can lead to significant increases in natural fertility rates, improving live birth rates by up to 2 fold. The aims of surgery are to remove all visible endometriosis (to decrease the endometriosis load) and restore normal pelvic anatomy.

Severe endometriosis, especially where the bowel is involved, is one of the most challenging types of surgery that Gynaecological Surgeons perform and requires special training. It is important in this scenario to adopt a multi-disciplinary approach to give the patient the best results.

Assisted Conception (OI/IUI and IVF) have also demonstrated significant benefits in women with endometriosis. IVF is a commonly utilised treatment option to help achieve a successful pregnancy in women with endometriosis.

Both Laparoscopic Surgery and IVF are useful to help a couple with endometriosis conceive. The exact strategy depends on a number of factors which need to be tailored to a particular couple and this would be best assessed by a Fertility Specialist and Gynaecological Surgeon with expertise in Endometriosis.

Are there any risks associated with treatment?
The decision between Laparoscopic Surgery and IVF in women with endometriosis trying to conceive needs to be tailored to a particular couple’s goals. Whilst there are risks to any treatments offered, it is only when the benefits of treatment significantly outweigh the risk that we decide to proceed.

Endometriosis is a common, chronic disease with no cure, so we have to treat the woman with a holistic, tailored, long term approach.

This can be seen as a complete Circle of Care - Laparoscopic Surgery and IVF can help achieve pregnancy. Once pregnancy is achieved, pregnancy itself is a treatment for endometriosis (as there is less hormonal fluctuations).

When the baby is delivered, it is important to manage the inter-pregnancy interval to prevent endometriosis recurrence, generally with medical treatments. Because these medical treatments are generally contraceptive, when a couple wants to conceive again, we stop the medical treatments and the Circle of Care starts again.