Pelvic Pain (Dysmenorrhea)

Essentials of Diagnosis

• Primary dysmenorrhea is menstrual pain associated with menstrual cycles in the absence of pathologic findings

• Other causes of pelvic pain may present during the menstrual cycle or be more chronic, including

  • Endometriosis

  • Fibroids

  • Pelvic inflammatory disease (PID)

  • Anatomic abnormalities of other pelvic organs, including the bowels or bladder

General Considerations

PRIMARY DYSMENORRHEA

• The pain usually begins within 1–2 years after the menarche and may become progressively more severe

• The pain is produced by uterine vasoconstriction, anoxia, and sustained contractions mediated by prostaglandins

Demographics

PRIMARY DYSMENORRHEA

• The frequency of cases increases up to age 20 and then decreases with both increasing age and parity

• Overall, 50% to 75% of women are affected at some time, and 5–6% have incapacitating pain

Symptoms and Signs

PRIMARY DYSMENORRHEA

• Pain is low, midline, wave-like, cramping pelvic pain often radiating to the back or inner thighs

• Cramps may last for 1 or more days and may be associated with nausea, diarrhea, headache, and flushing

• Pelvic examination reveals no pathologic findings

OTHER CATEGORIES OF PELVIC PAIN

• The history and physical examination commonly suggest endometriosis, adenomyosis, or fibroids

• Other causes may be pelvic inflammatory disease, tubo-ovarian abscess, submucous myoma, cervical stenosis with obstruction, or blind uterine horn (rare)

Differential Diagnosis

• Endometriosis

• Adenomyosis

• Pelvic inflammatory disease

• Uterine leiomyomas (fibroids)

• IUD

• Pelvic pain syndrome

• Endometrial polyp

• Cervicitis

• Cervical stenosis

• Cystitis

• Interstitial cystitis

Imaging Studies

• Pelvic imaging is useful in detecting uterine fibroids or other anomalies

• Ultrasound or, preferably, MRI is useful in identifying adenomyosis

Diagnostic Procedures

OTHER CATEGORIES OF PELVIC PAIN

• Laparoscopy may help diagnose endometriosis or other pelvic abnormalities not visualized by imaging

Medications

PRIMARY DYSMENORRHEA

• Nonsteroidal anti-inflammatory drugs (ibuprofen, ketoprofen, mefenamic acid, naproxen) and the COX-2 inhibitor celecoxib are generally helpful

• Drugs should be started 1–2 days before expected menses

• Symptoms can be suppressed by

  • Combined oral contraceptives

  • Depot-medroxyprogesterone acetate

  • Etonogestrel subdermal (Nexplanon)

  • Levonorgestrel-containing IUD

• Oral contraceptives can be administered continuously to suppress menstruation completely and prevent dysmenorrhea

• For women who do not wish to use hormonal contraception, other therapies that have shown at least some benefit include

  • Local heat

  • Thiamine, 100 mg/day orally

  • Vitamin E, 200 units/day orally from 2 days prior to and for the first 3 days of menses

  • High-frequency transcutaneous electrical nerve stimulation

OTHER CATEGORIES OF PELVIC PAIN

• Combined estrogen and progestin and progestin-only hormonal contraceptives are first-line therapies for alleviating the symptom of dysmenorrhea

• Periodic use of analgesics, including the nonsteroidal anti-inflammatory drugs given for primary dysmenorrhea, may be beneficial

• Gonadotropin-releasing hormone agonists

  • Effective in the treatment of endometriosis

  • Long-term use may be limited by cost or side effects

• Levonorgestrel-releasing intrauterine system (LNG-IUS), uterine artery embolization, or hormonal approaches used to treat endometriosis are used to treat adenomyosis

Surgery

• If disability is marked or prolonged, diagnostic laparoscopy is usually warranted

• Definitive surgery depends on the degree of disability and the findings at operation

• Uterine artery embolization can be done to remove or treat uterine fibroids

• Hysterectomy may be done if other treatments have not worked but is usually a last resort

Therapeutic Procedures

• Other modalities that may be helpful in primary dysmenorrhea include local heat and high-frequency transcutaneous electrical nerve stimulation

• Cervical stenosis may result from induced abortion, creating crampy pain at the time of expected menses with no blood flow; this is easily cured by passing a sound into the uterine cavity after administering a paracervical block

When to Refer

• Standard therapy fails to relieve pain

• Suspicion of pelvic pathology, such as endometriosis, leiomyomas, or adenomyosis