Endometriosis: Definition and Stages, Symptoms, Causes and Risk Factors

Endometriosis is the cause of pelvic pain (dysmenorrhea, dyspareunia) and infertility in over 35% of women of reproductive age, but the exact prevalence of the disease is unknown because surgical visualization is required to make a definitive diagnosis. In the general population, prevalence is estimated at around 10% of women. It is estimated that between 71% and 87% of women with chronic pelvic pain have endometriosis and that about 38% of women with infertility have the disorder. The disease usually occurs during the reproductive years, but has been documented in a wide range of ages between 8 and 76 years, with some cases before menarche

Endometriosis was once called the "career woman disease" because it was thought to be a product of delayed motherhood. Statistics challenge such a narrow generalization; however, pregnancy can delay the advancement of the condition. Women whose periods last more than a week with an interval of less than 27 days between them seem to be more prone to the condition

Endometrial implants are most often found in the pelvic organs, including the ovaries, uterus, fallopian tubes, intestines, and the cavity behind the uterus. Occasionally, this tissue grows in parts distant from the body such as the lungs, arms and kidneys

Definition of Endometriosis

Endometriosis is a condition in which pieces of tissue similar to the lining of the uterus (endometrium) grow in other parts of the body (and inside the uterus). Like the uterine lining, this tissue builds up and disperses in response to monthly hormonal cycles. The blood discarded by these implants falls on the surrounding organs, causing swelling and inflammation. Also, repeated irritation causes the development of scar tissue and adhesions

Endometriosis is defined as the presence of endometrial glands or stroma outside the endometrial cavity and uterine musculature. Its presence is suggested by a history of dyspareunia (painful intercourse), worsening dysmenorrhea that often begins before menstruation or by a thickened rectovaginal septum or deviation of the cervix from the pelvic exam

Mild endometriosis does not appear to affect fertility; The pathogenesis of infertility associated with moderate and severe endometriosis can be multifactorial with alterations in folliculogenesis, fertilization and implantation, as well as adhesions. However, endometriosis is often clinically silent and can be definitively excluded from laparoscopy

Ovarian cysts can form around endometrial tissue (endometriomas) and can vary from the size of the pea to the grapefruit. Endometriosis is a progressive condition that generally progresses slowly over many years. Doctors evaluate minimal to severe cases based on factors such as the number and size of endometrial implants, their appearance and location, as well as the extent of scar tissue and adhesions near the growths

Stages of Endometriosis

There are numerous classification systems for assessing the severity of the disease. Each system has its advantages and disadvantages, and a perfect system has not yet been devised that is accurately related to the severity of the symptoms. The most used is the one developed by the American Society for Reproductive Medicine (ASRM), in which points are awarded for endometriotic lesions, periodic adhesions and Douglas obliteration pocket

The total score is used to describe the disease as minimal (Phase 1), mild (Phase 2), moderate (Phase 3) or severe (Phase 4). This system was designed to aid in the prognosis and management of patients undergoing subfertility surgery. Deep infiltrating endometriosis (DIE), one of the main causes of pelvic pain and dyspareunia, is generally assigned a low score (Stage 1 or 2) because only visible lesions contribute; This partly explains why there is little correlation between total score and pain severity

• Stage I (minimum): Endometriosis is considered "minimum". The implants are small, few and shallow, although it is noted that these stages do not correspond to the levels of pain and discomfort

• Stage II (mild): There are more implants than in stage 1. They are also deeper in the tissue and there may be scar tissue

• Stage III (moderate): There are numerous deep implants. There may be small cysts on one or both ovaries and thick bands of scar tissue called adhesions

• Stage IV (severe): "Severe" stage of endometriosis. additionally  to many deep endometriosis implants, there are large cysts on at least one ovary, and many dense adhesions throughout the pelvic region

Symptoms of Endometriosis

While many women with endometriosis have debilitating symptoms, others have the disease without knowing it. Interestingly, there appears to be no relationship between the severity of the symptoms and the extent of the disease. The main symptoms of endometriosis are pain and infertility. The pain is generally cyclical, following the pattern of the menstrual cycle, and can be moderate to debilitating, especially during menstruation. Distant endometrial implants also cause pain as they swell and bleed

The pain associated with endometriosis is secondary to structural and / or inflammatory causes. Injuries can cause pain from compression of nerve fibers. The increase in pressure inside the endometriomas (cysts inside the ovary) has been linked to dyspareunia. Endometrial lesions also generate local inflammation with the release of prostaglandins and increase the risk of developing adhesions, endometrial lesions contain estrogen and progesterone receptors, and symptoms may be related to the release of cyclic hormones during the menstrual cycle

Symptoms

• Asymptomatic
• Dysmenorrhea
• Dyspareunia
• Chronic pelvic pain (cyclic or acyclic)
• Premenstrual spotting
• Gastrointestinal complaints
• Urinary disorders (dysuria, hematuria)
• Low back pain
• Painful defecation (discecia)

Signs

• Sensitivity to the cul de sac or to the uterosacral ligament
• Adneal enlargement or tenderness
• Pelvic mass
• Subfertility

Causes of Endometriosis

The etiology of endometriosis is unknown. It has often been called the disease of theories, due to the many theories postulated to explain its pathogenesis. The mechanism for the development of these lesions is probably multifactorial and includes theories of retrograde menstrual flow, celiac metaplasia, lymphatic and vascular diffusion and immunological abnormalities

• Plant theory. This theory states that a reversal in the direction of menstrual flow sends discarded endometrial cells to the body cavity where they join, internal organs and endometrial seed implants. There is considerable evidence to support this explanation

• Theory of celomial metaplasia. According to this hypothesis, the remains of tissue that remain from the prenatal development of the female reproductive tract are transformed into endometrial cells throughout the body

• Vascular-lymphatic theory. This theory suggests that the lymphatic system or blood vessels (vascular system) are the vehicles for the distribution of endometrial cells outside the uterus

• Immunology. The researchers also found alterations in cellular and humoral immunity in women with endometriosis. Affected patients have been shown to exhibit increased macrophage activation, decreased T cells and natural killer cell function and increased autoantibody levels. The importance of autoantibodies and immune system dysfunction is controversial and unclear

• Environmental toxins. A growing area of ​​interest is the role of environmental toxins, such as dioxin, in inducing endometriosis. Human studies have confirmed elevated dioxin levels in endometriosis patients compared to control patients. Molecular aberrations in the function of steroidogenic enzymes have been implicated in the development of endometriosis

Endometriosis Risk Factors

The factors that increase a woman's risk of endometriosis are unclear. Since endometriosis tends to run in families, researchers believe it may be the result of Genetic Preparation in combination with other undetermined factors. However, any woman who is menstruating can develop endometriosis. There are no measures to prevent endometriosis

Age

Age is the main determinant of endometriosis risk: the condition is rare before menarche and after menopause, being a condition of fertile age

Family History

The risk of endometriosis has been consistently shown to be higher in women whose mother or sister has the disease. The association between genetic predisposition and endometriosis was based on the retrospective analysis of family stories that indicate a multifactorial and polygenic inheritance model. In probands of affected families, the onset of endometriosis occurs earlier in life, with a more severe stage at endometriosis diagnosis. First degree relatives have an incidence rate of 6 to 9% compared to a rate of 1% for unrelated controls

Characteristics of the menstrual cycle

The greater the exposure to menstruation, the greater the chances of developing endometriosis. Factors that increase menstrual exposure, and therefore risk, include:

• Starting his first period before the age of 12
• Experience periods lasting seven days or more each month with an interval of less than 27 days between them

History of immune disorders

Some epidemiological data have also linked the risk of endometriosis with the frequency of immune disorders. If your immune system is weak, you are less likely to recognize misplaced endometrial tissue. Sparse endometrial tissue can be implanted in the wrong places. This can lead to problems like injury, inflammation and scarring

Conditions that interfere with normal menstrual flow

If you have a medical condition that increases, blocks or redirects menstrual flow, this could be a risk factor. Conditions that can cause retrograde menstrual flow include:

• Endometriosis is an estrogen-dependent disease; therefore, factors that lower estrogen levels (e.g. menstrual disorders, reduced body fat content and smoking) are associated with a lower risk of developing the condition.
• Uterine growths, such as fibroids or polyps
• Structural abnormality of the uterus, cervix or vagina
• Obstructions in the cervix or vagina
• Asynchronous uterine contractions