Endometriosis is a common yet often misunderstood gynaecological condition affecting millions of women globally, particularly during their reproductive years. It is a leading cause of chronic pelvic pain and, significantly, infertility.
Endometriosis occurs when tissue similar to the endometrium grows outside the uterus, often on the ovaries, fallopian tubes, and the pelvic peritoneum. It causes inflammation, scar tissue formation (adhesions), and sometimes cysts, particularly on the ovaries (known as endometriomas or ‘chocolate cysts’).
Impact on fertility
According to estimates, 30-50% of women with endometriosis struggle with infertility, making it one of the most common causes of reproductive challenges The exact mechanism by which endometriosis impairs fertility is unknown.
One of the most direct ways it can lead to infertility is through the distortion of the pelvic anatomy. Adhesions and scar tissue can form between the reproductive organs. This can block the fallopian tubes, preventing the egg and sperm from meeting, or impairing the movement of the embryo towards the uterus. Endometriomas on the ovaries can also affect ovulation, either by damaging ovarian tissue or causing the release of poor-quality eggs.
Endometriosis is associated with chronic inflammation in the pelvic cavity, which can have several negative effects on fertility. Elevated levels of pro-inflammatory cytokines and immune cells can impair sperm motility and function, making it more difficult for sperm to reach and fertilise the egg. Inflammation may interfere with normal embryo implantation in the uterine lining.
Hormonal dysregulation is another significant factor in the infertility associated with endometriosis. The condition is associated with elevated levels of oestrogen and reduced levels of progesterone. Oestrogen stimulates the growth of endometriotic lesions, while a relative lack of progesterone may impair the ability of the endometrium to support implantation and early pregnancy. These hormonal imbalances may also contribute to irregular ovulation or poor-quality eggs.
Women with advanced stages of endometriosis (Stage III and IV) may experience a decline in their ovarian reserve – an estimate of the number and quality of a woman’s remaining eggs. This decline is partly due to the damaging effects of endometriomas on ovarian tissue. Studies have shown that the ovarian environment in women with endometriosis may also impair egg quality, leading to lower rates of successful fertilisation and embryo development.
Diagnosis and treatment options
Diagnosis is often delayed due to the variable nature of its symptoms. While pelvic pain and painful periods are hallmark symptoms, some women may have mild or no symptoms, making it difficult to identify the condition without a thorough evaluation. A definitive diagnosis of endometriosis often requires a laparoscopy, a minimally invasive surgical procedure that allows a surgeon to directly visualise and biopsy the endometrial lesions.
Women with endometriosis have several infertility treatment options depending on the severity of the disease and the individual’s reproductive goals.
Laparoscopic surgery is often considered for women with endometriosis who are trying to conceive. During surgery, the endometriosis surgeon can remove or destroy endometrial lesions, adhesions, and cysts, potentially improving fertility outcomes.
Research suggests that removing endometriomas and other lesions can restore a more normal pelvic anatomy, enhance ovarian function, and increase the chances of natural conception. About 60% of couples with stage I and II endometriosis may conceive naturally within six months provided there is no other associated factors for infertility. However, stage III and IV endometriosis cases are often referred for assisted reproduction.
For women who struggle to conceive with endometriosis, assisted reproductive technologies (ART) such as in vitro fertilisation (IVF) may be recommended. IVF bypasses many of the anatomical barriers and inflammation-related issues seen in endometriosis.
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For instance, IVF allows eggs to be retrieved directly from the ovaries, fertilised in the laboratory, and transferred into the uterus, circumventing any blockages in the fallopian tubes. Studies show that IVF success rates in women with endometriosis are lower than in women without the condition, but it remains one of the most effective fertility treatments.
Egg freezing is an option for women with endometriosis who wish to protect their future fertility. It is important to assess ovarian reserve (AMH level) for patients with endometriosis as it can be a potential guide for those wishing to protect fertility.
Hormonal treatments such as oral contraceptives, gonadotropin-releasing hormone (GnRH) agonists and antagonists, and progestins can effectively manage the symptoms of endometriosis but are generally not used as a fertility treatment. These therapies suppress ovulation and reduce the production of oestrogen, helping to shrink or suppress endometrial lesions. However, since they also prevent pregnancy, they are typically reserved for women who are not actively trying to conceive.
Author competing interests – nil
Key messages
- Women with endometriosis, experiencing infertility have several treatment options
- Early diagnosis and a tailored treatment plan are critical for improving reproductive outcomes
- With the right approach, many women with endometriosis can successfully conceive and build the families they desire.
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