Endometriosis

By Dr. Christopher Ng
Obstetrician and Gynaecologist
MBBS (London, UK), FRANZCOG (Aust-NZ), MMed (S'pore), FAMS (S'pore)

1. What is endometriosis?

Endometriosis is a common medical condition characterized by growth of endometrium (the tissue that normally lines the uterus) beyond or outside the uterus. It looks and acts like tissue in the uterus. It most often appears in places within the pelvis:

• Ovaries
• Fallopian tubes
• Surface of the uterus
• Cul-de-sac(space behind the uterus)
• Bowel
• Bladder and ureters
• Rectum

Endometrial tissue may attach to organs in the pelvis or to the peritoneum, the tissue that lines the inside of pelvis and abdomen. In rare cases, it also may be found in other parts of the body. Endometrial tissue that grows in the ovaries may cause a cyst (endometriotic cyst) to form.

Endometrial tissue outside the uterus responds to changes in hormones. It breaks down and bleeds like the lining of the uterus during the menstrual cycle. The breakdown and bleeding of this tissue each month can cause scar tissue, known as adhesions.

Adhesions can cause pain. Sometimes, adhesions bind organs together.

The symptoms of endometriosis often worsen over time. In many cases, treatment may prevent the condition from getting worse.

2. What causes endometriosis?

The causes of endometriosis are still unknown. A common belief is due to retrograde flow of menstrual blood to the pelvic cavity

3. What are the signs and symptoms of endometriosis?

Women may complain of the following:

• Heavy and sometimes irregular menses
• Painful periods
• Pain during sex (this is a deep pain during penetration)
• Pain in the pelvis or lower abdomen in between periods
• It may be associated with infertility.

It is estimated that 30-40% of women with endometriosis may have difficulties in becoming pregnant i.e. unable to conceive after 1 year of regular intercourse. The age- dependent cycle fecundity (monthly) rates in healthy fertile women range between 15 and 25%. That chance is less than 1% for women with severe endometriotic disease.

4. How common is endometriosis?

The prevalence of endometriosis is around 5%-20% of women of reproductive age. About 30% to 40% of women with endometriosis are infertile.

5. Is there any age group which is more prone to endometriosis?

It is more common in women of reproductive age between 20s-40s. The literature seems to indicate that Caucasian women are at greater risk of developing endometriosis than Afro-Carribean.

6. Is there a cure for endometriosis?

As endometriosis is hormonally related, there is no permanent cure for endometriosis short of natural menopause or surgical menopause (by removing the ovaries) but even then there are reports of endometriosis found in menopausal women although rare. There are however treatments to help women manage and deal with their symptoms. For some women pregnancy can lessen the symptoms and effects of endometriosis. The reality is that pregnancy, like hormonal drug treatments, usually suppresses the symptoms of endometriosis but does not eradicate the disease itself.

Symptoms may or may not recur after the birth of the child. Most women can delay the return of symptoms by breastfeeding, but only while the breastfeeding is frequent enough and intense enough to suppress the menstrual cycle. Doctors sometimes advise women with endometriosis not to delay having children because endometriosis tends to worsen with time. The longer you have endometriosis, the greater your chance of becoming infertile.

7. How is endometriosis diagnosed?

Besides a thorough history to determine if you have any characteristic symptoms to suggest the presence of endometriosis, your gynaecologist will perform a pelvic exam. This is to try to localize the area of pelvic pain. Other causes of pelvic pain would have to be ruled out. A pelvic ultrasound scan can be used to detect endometriotic cysts and this is usually combined with blood Ca125 investigation (which can be raised in endometriosis).

Endometriosis can be mild, moderate, or severe. The extent of the disease can be confirmed by looking directly inside the pelvis using a laparoscopy (key hole surgery). You will be given general anesthesia for these procedures. The endometriotic lesions as well as endometriotic cysts and adhesions can also be removed during a laparoscopy.

8. What are the surgical and non-surgical treatment available?

Treatment is directed at either relief of pain or infertility. The treatment options for pain range from:

• Analgesics (Pain killer)
• Combined oral contraceptive pill
• Progression intrauterine device (Mirena)
• Danazol (Amle hormone compound)
• Oral progesterone (Visanne)
• Depot progesterone injections (Depoprovera)
• Gonadotropin-releasing hormone (GnRH) agonists — to create a tesendo menopausal state

They are equally effective but their side-effect and cost profiles differ. Suppression of ovarian function with any of these medications for several months reduces endometriosis-associated pain.

Surgery may be advisable for some women in whom medical treatment has failed to relieve their pain or infertility. The goal of surgery is to remove or coagulate all visible endometriotic peritoneal lesions, endometriotic ovarian cysts, deep rectovaginal endometriosis and associated adhesions, and to restore normal anatomy. Ablation of endometriotic lesions plus removal of endometriotic adhesions to improve fertility in endometriosis is effective. Laparoscopic surgery can almost double the chance of pregnancy and a live birth for women with mild endometriosis compared with not having the surgery. Following surgery, rates of pregnancy for women with mild endometriosis as their only fertility problem range from 81% to 84%. Those with moderate or severe endometriosis, including damage to the ovaries, have a 36% to 66% chance of conceiving after surgery. Pregnancy rates are highest within a year of surgery, since endometriosis commonly recurs in spite of the operation.

In addition, SOIUI (superovulation intra-uterine insemination) or IVF (in vitro fertilisation) may be required in women who fail to conceive following surgery. Treatment with SOIUI improves fertility in minimal to mild endometriosis but tubal patency is a prerequisite. IVF is appropriate treatment, especially if the tubes are blocked, if there is also male factor infertility, and/or other treatments have failed.