Key facts
- Endometriosis is a disease where tissue similar
to the lining of the uterus grows outside the uterus, causing pain
and/or infertility (1).
- Endometriosis affects roughly 10% (190 million) of reproductive age women and girls globally (2).
- It is a chronic disease associated with severe,
life-impacting pain during periods, sexual intercourse, bowel movements
and/or urination, chronic pelvic pain, abdominal bloating, nausea,
fatigue, and sometimes depression, anxiety, and infertility.
- The variable and broad symptoms of endometriosis
mean that healthcare workers do not easily diagnose it and many
individuals suffering from it have limited awareness of the condition.
This can cause a lengthy delay between onset of symptoms and diagnosis
(3).
- At present, there is no known cure for endometriosis, and treatment is usually aimed at controlling symptoms (4).
- Access to early diagnosis and effective
treatment of endometriosis is important, but is limited in many
settings, including in low- and middle-income countries.
- There is a need for more research and awareness
raising around the world to ensure effective prevention, early
diagnosis, and improved management of the disease (2,5).
Introduction and definition
Endometriosis is a
disease characterized by the presence of tissue resembling endometrium
(the lining of the uterus) outside the uterus (1). It causes a chronic
inflammatory reaction that may result in
the formation of scar tissue (adhesions, fibrosis) within the pelvis
and other parts of the body. Several lesion types have been described
(1,6):
- superficial endometriosis found mainly on the pelvic peritoneum
- cystic ovarian endometriosis (endometrioma) found in the ovaries
- deep endometriosis found in the recto-vaginal septum, bladder, and bowel
- in rare cases, endometriosis has also been found outside the pelvis
Symptoms associated with endometriosis vary, and include a combination of:
- painful periods
- chronic pelvic pain
- pain during and/or after sexual intercourse
- painful bowel movements
- painful urination
- fatigue
- depression or anxiety
- abdominal bloating and nausea
In
addition to the above, endometriosis can cause infertility. Infertility
occurs due to the probable effects of endometriosis on the pelvic
cavity, ovaries, fallopian tubes or uterus. There is little correlation
between the extent of endometrial
lesions and severity or duration of symptoms: some individuals
with visibly large lesions have mild symptoms, and others with few
lesions have severe symptoms. Symptoms often improve after menopause,
but in some cases painful symptoms can persist.
Chronic pain may be due to pain centres in the brain becoming
hyper-responsive over time (central sensitisation), which can occur at
any point throughout the life course of endometriosis, including
treated, insufficiently treated, and untreated
endometriosis, and may persist even when endometriosis lesions
are no longer visible. In some cases, endometriosis can be asymptomatic.
What is the cause of endometriosis?
Endometriosis
is a complex disease that
affects some women globally, from the onset of their first
period (menarche) through menopause regardless of ethnic origin or
social status. The exact origins of endometriosis are thought to be
multifactorial, meaning that many different factors
contribute to its development. Several hypotheses have been
proposed to explain origins of endometriosis. At present endometriosis
is thought to arise due to:
- Retrograde menstruation, which
is when menstrual blood containing endometrial cells flows back through
the fallopian tubes and into the pelvic cavity at the time that blood is
flowing out of the body through the cervix and vagina during periods.
Retrograde menstruation can result in endometrial-like cells
being deposited outside the uterus where they can implant and grow.
- Cellular
metaplasia, which is when cells change from one form to another. Cells
outside the uterus change into endometrial-like cells and start to grow.
- Stem cells giving rise to the disease, which then spreads through the body via blood and lymphatic vessels.
Other
factors may also contribute to the growth or persistence of ectopic
endometrial tissue. For example, endometriosis is known to be dependent
on estrogen, which facilitates the inflammation, growth, and pain
associated with the disease. However,
the relationship between estrogen and endometriosis is complex
since the absence of estrogen does not always preclude the presence of
endometriosis. Several other factors are thought to promote the
development, growth, and maintenance of endometriosis
lesions. These include altered or impaired immunity, localized
complex hormonal influences, genetics and potentially, environmental
contaminants (2,7).
Health, social and economic benefits of addressing endometriosis
Endometriosis
has significant social, public health and economic implications. It can
decrease quality of life due to severe pain, fatigue, depression,
anxiety, and infertility. Some individuals with endometriosis experience
debilitating endometriosis-associated
pain that prevents them from going to work or school (8,9). In
these situations, addressing endometriosis can reduce absence from
school or increase an individual’s ability to contribute to the labour
force. Painful sex due to endometriosis
can lead to interruption or avoidance of intercourse and affect
the sexual health of affected individuals and/or their partners (9).
Addressing endometriosis will empower those affected by it, by
supporting their human right to the highest standard
of sexual and reproductive health, quality of life, and overall
well-being.
Prevention
At present, there is
no known way to prevent endometriosis. Enhanced awareness, followed by
early diagnosis and management
may slow or halt the natural progression of the disease and
reduce the long-term burden of its symptoms, including possibly the risk
of central nervous system pain sensitisation, but currently there is no
cure.
Diagnosis
A careful history of
menstrual symptoms and chronic pelvic pain provides the basis for
suspecting endometriosis. Although several screening tools and tests
have been proposed and tested, none are currently validated
to accurately identify or predict individuals or populations
that are most likely to have the disease. Early suspicion of
endometriosis is a key factor for early diagnosis, as endometriosis can
often present symptoms that mimic other conditions
and contribute to a diagnostic delay. In addition to medical
history, referral from the primary health care level to secondary
centers where additional investigations are available may be needed. For
instance, ovarian endometrioma, adhesions and
deep nodular forms of disease often require ultrasonography or
magnetic resonance imaging (MRI) to detect. Histologic verification,
usually following surgical/laparoscopic visualization, can be useful in
confirming diagnosis, particularly for
the most common superficial lesions (1,2). The need for
histologic/laparoscopic confirmation should not prevent the commencement
of empirical medical treatment.
Treatment
Treatment
can be with medications and/or
surgery depending on symptoms, lesions, desired outcome, and
patient choice (4). Contraceptive steroids, non-steroidal
anti-inflammatory medications, and analgesics (painkillers) are common
therapies. All must be carefully prescribed and monitored
to avoid potentially problematic side effects. Medical
treatments for endometriosis focus on either lowering estrogen or
increasing progesterone in order to alter hormonal environments that
promote endometriosis. These medical therapies include
the combined oral contraceptive pill, progestins, and
GnRH-analogues. However, none of these treatments eradicates the
disease, they are associated with side effects, and
endometriosis-related symptoms can sometimes - but not always - reappear
after therapy discontinuation. The choice of treatment depends
on effectiveness in the individual, adverse side effects, long-term
safety, costs, and availability. Most current hormonal management is not
suitable for persons suffering from endometriosis
who wish to get pregnant, since they affect ovulation.
Surgery
can remove endometriosis lesions, adhesions, and scar tissue. However,
success in reducing pain symptoms and increasing pregnancy rates are
often dependent on the extent
of disease. In addition, lesions may recur even after successful
eradication, and pelvic floor muscle abnormalities can contribute to
chronic pelvic pain. Secondary changes of the pelvis, including the
pelvic floor, and central sensitisation may
benefit from physiotherapy and complementary treatments in some
patients. Treatment options for infertility due to endometriosis include
laparoscopic surgical removal of endometriosis, ovarian stimulation
with intrauterine insemination (IUI),
and in vitro fertilization (IVF), but success rates vary (4).
Other comorbidities may occur alongside endometriosis, requiring
diagnosis and management. Multidisciplinary treatment addressing
different symptoms and overall health should
involve different specialists, such as pain specialists, pelvic
physiotherapists, complementary and alternative medicine specialists,
general practitioners, and psychologists, in addition to gynaecologists,
to be most effective (2,10).
Addressing current challenges and priorities
In
many countries, the general public and most front-line healthcare
providers are not aware that distressing and life-altering pelvic pain
is not normal, leading to a normalisation
and stigmatisation of symptoms and significant diagnostic delay
(2,3). Patients who could benefit from medical symptomatic management
are not always provided with treatments due to limited awareness of
endometriosis among primary healthcare providers.
Due to diagnostic delays, prompt access to available treatment
methods, including non-steroidal analgesics (painkillers), oral
contraceptives and progestin-based contraceptives is often not achieved.
Due to limited capacity of health systems in
many countries, access to specialised surgery for those who need
it is sub-optimal. In addition, and especially in low and middle-income
countries, there is a lack of multi-disciplinary teams with the wide
range of skills and equipment needed
for the early diagnosis and effective treatment of
endometriosis. Although primary health care professionals should play a
role in screening and basic management of endometriosis, tools to screen
and accurately predict patients and populations
who are most likely to have the disease are lacking. In
addition, many knowledge gaps exist, and there is need for non-invasive
diagnostic methods as well as medical treatments that do not prevent
pregnancy.
Subsequently, some of the
current priorities related to endometriosis include:
- Raising
awareness about endometriosis among health care providers, women, men,
adolescents, teachers and wider communities. Local, national and
international information campaigns to educate the public and healthcare
providers about normal and
abnormal menstrual health and symptoms are needed.
- Training
all healthcare providers to improve their competency and skills to
screen, diagnose, manage, or refer patients with endometriosis. This can
range from basic training of primary healthcare providers to recognize
endometriosis, to the advanced
training of specialist surgeons and multidisciplinary teams.
- Ensuring that primary health care plays a role in screening,
identifying and providing basic pain management of endometriosis, in
situations where gynaecologists or advanced multidisciplinary
specialists are unavailable.
- Advocating for health policies
that ensure access to at least a minimum level of treatment and support
for patients with endometriosis.
- Setting up referral systems and
care pathways consisting of well-linked primary healthcare centres and
secondary and tertiary centres with advanced imaging, pharmacologic,
surgical, fertility and multi-disciplinary interventions.
- Strengthening
capacity of health systems to achieve early diagnosis and management of
endometriosis by enhancing availability of equipment (e.g. ultrasound
or magnetic resonance imaging) and pharmaceuticals (e.g. non-steroidal
analgesics, combined
oral contraceptives and progestin-based contraceptives).
- Increasing
research on the pathogenesis, pathophysiology, natural progression,
genetic and environmental risk factors, prognosis, disease
classification, non-invasive diagnostic biomarkers, personalized
treatments and other treatment paradigms,
role of surgery, novel targeted therapeutics, curative
therapies, and preventive interventions in endometriosis (2,5).
- Accelerating
collaborative global action to improve access to reproductive health
care for women globally, including in low- and middle-income countries.
WHO response
The
World Health Organization (WHO) recognizes the importance of
endometriosis and its impact on people’s sexual and reproductive health,
quality of life, and overall well-being. WHO aims to stimulate and
support
the adoption of effective policies and interventions to address
endometriosis globally, especially in low and middle-income countries.
WHO is partnering with multiple stakeholders, including academic
institutions, non-state actors and other organizations
that are actively involved in research to identify effective
models of endometriosis prevention, diagnosis, treatment, and care. WHO
recognises the importance of advocating for increased awareness,
policies and services for endometriosis, and
collaborates with civil society and endometriosis patient
support groups in this regard. WHO is also collaborating with relevant
stakeholders to facilitate and support the collection and analysis of
country- and region-specific endometriosis prevalence
data for decision making.
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