Endometriosis occurs in approximately 8% of reproductive-age women and can have severe consequences, including chronic pelvic pain and infertility. It occurs in approximately one-third of infertile women and up to 87% of women with chronic pelvic pain.
Dr. Neil Skolnik and Dr. Jennifer Thuener
Clinical Manifestations
Pelvic pain is a common complaint in the outpatient office. Symptoms of endometriosis include dysmenorrhea, cyclic chronic pelvic pain, and dyspareunia that is worse during menses.
Diagnosis
Frequently, there are no abnormalities on physical exam that would indicate endometriosis, and labs typically are normal. It is important to consider other diagnoses, including irritable bowel syndrome, interstitial cystitis, and tubal scarring secondary to pelvic inflammatory disease.
Consideration can be given to obtaining a CBC, urinalysis, and gonococcal and chlamydia testing. Pelvic imaging is of limited use but can be considered as part of the initial work-up. If there is an adnexal mass on palpation, imaging studies are accurate in differentiating an endometrioma from other masses. Ultrasound is best utilized in determining the presence of an endometrioma on the ovary in a fertility work-up, rather than as an initial diagnostic tool of endometriosis.
The only definitive way to diagnose endometriosis is through laparoscopy and a histologic examination. Visual examination with laparoscopy or surgery can be helpful, but studies have shown discrepancies between visual assessment and histologic findings. The importance of laparoscopy to diagnose endometriosis has been debated in the literature, with investigators weighing the impression and risks of surgery against the importance of a precise diagnosis when treating with medications.
Medical Treatment
When a woman presents to the office with symptoms consistent with endometriosis, the initial plan should be control of pain and preservation of future fertility. There is no need to verify the diagnosis of endometriosis with imaging or surgery prior to starting therapy.
The first-line therapy in a woman in whom a clinical diagnosis has been made and who has mild symptoms is NSAIDs. If NSAIDs are not sufficient to control pain, then the next line of therapy is oral contraceptives. If the patient is having pain with the withdrawal bleed associated with OCs, then continuous OCs may be beneficial. There is evidence that continuous therapy can provide a significant reduction in pain after a woman has failed cyclic OC therapy.
If first-line treatment with NSAIDs and OCs fails, consider laparoscopic surgery to confirm a diagnosis of endometriosis. An alternative approach includes more empiric therapy or attempting other medical therapies.
Gonadotropin-releasing hormone (GnRH) analogues are effective in reducing dysmenorrhea. But they are no more effective than OCs, and have greater associated side effects, including hot flashes, vaginal dryness, and osteopenia.
When relief of pain supports ongoing therapy, the addition of progestins as add-back therapy decreases bone density loss and side effect–related symptoms without compromising symptomatic efficacy. Add-back therapy can be started concurrently with the GnRH analogues. It should be noted that the Food and Drug Administration has approved GnRH agonist therapy for a 12-month course only.
Depo medroxyprogesterone acetate (DMPA) is also effective suppressive therapy, though it’s less preferred by women looking to become pregnant soon, as there may be a long delay until return to ovulation. It also can be used for a limited time only, and has the side effect of osteopenia.
The levonorgestrel IUD is effective in reducing pain associated with endometriosis, and it has shown persistent benefit at 3 years. The IUD is no better or worse than the GnRH analogues; however, many women discontinue use of the IUD because of weight gain, irregular bleeding, or pain. The IUD does not have FDA approval for the treatment of endometriosis.
Androgens such as danazol are effective treatment but have undesirable side effects, including acne, hirsutism, and myalgias. Therefore, they are not recommended as a first-line therapy.
Surgical Treatment
While surgery may need to be considered in patients with severe pain that is unresponsive to medical treatment, it is not a first-line therapy. Surgery is also considered as the choice of therapy when a woman is suffering from endometriosis-induced infertility and is attempting to conceive.
Such infertility is thought to be due to the presence of an endometrioma on the ovary. Because the endometrioma can invade the ovary, it must be explained to the patient that removing an endometrioma may remove ovarian tissue. There is evidence that an excision of the endometrioma will give a better pregnancy rate than a simple ablation of the cyst, as an endometrioma is likely to reform after an ablation. Although the data do show that there is an improvement in pregnancy rates after surgery, the extent of benefit is not as clear.