Chronic Pelvic Pain Syndrome in Women

Chronic pelvic pain syndrome in women is persistent, non-cyclical (or cyclical) pain perceived in structures related to the pelvis, lasting 6 months or longer. It is of sufficient severity to cause functional disability or require treatment, and is not due to pregnancy or primary dysmenorrhoea alone. Prevalence is about 14 to 24 percent in reproductive age women.

It is a multifactorial, often central sensitisation driven condition. Contributors include:

• Gynaecological: endometriosis, adenomyosis, adhesions, pelvic inflammatory disease, pelvic congestion.
• Urological: interstitial cystitis or bladder pain syndrome, urethral syndrome.
• Gastrointestinal: irritable bowel syndrome, constipation, inflammatory bowel disease.
• Musculoskeletal: myofascial pain of pelvic floor, abdominal wall nerve entrapment, pubic symphysis, hip pathology.
• Neurological: pudendal neuralgia.
• Psychological: abuse history, depression, anxiety, post-traumatic stress.

In about 40 percent no organic cause is found at laparoscopy. When a specific cause such as endometriosis is found, it is treated as such. The syndrome diagnosis applies when no clear pathology explains the pain, or the pain is disproportionate to the disease.

• Chronic lower abdominal or pelvic pain, dull or aching or burning, constant or intermittent, with sharp exacerbations; pain may be cyclical or non-cyclical.
• Dyspareunia (deep or superficial), dysmenorrhoea, dyschezia, dysuria, urinary frequency, urgency, bloating, constipation or diarrhoea.
• Pain aggravated by prolonged sitting, standing, exercise, stress and bowel or bladder filling.
• Fatigue, sleep disturbance, low mood, anxiety, and associated pain disorders (fibromyalgia, migraine, back pain, temporomandibular disorder).
• Examination: abdominal wall tenderness (Carnett sign: pain persisting or increasing on abdominal wall tensing indicates abdominal wall origin), pelvic floor muscle tenderness and tightness on vaginal palpation (levator ani, obturator internus, piriformis), cervical motion tenderness, uterosacral nodularity, fixed retroverted uterus, adnexal tenderness, vulvar allodynia.
• Past history of abuse, surgery, pelvic infection, or childbirth injury should be asked about sensitively.

• Take a detailed pain history: onset, location, character, relation to menses, bowel, bladder and intercourse, aggravating and relieving factors, previous investigations and treatments. Use pain diaries and validated pain scores. Assess psychological state (depression, anxiety, trauma screening), sleep and function.
• Abdominal and pelvic examination, including the pelvic floor muscles and abdominal wall, spine and hip examination, and sensory testing.
• Investigations: pregnancy test, urinalysis and culture, vaginal and cervical swabs for chlamydia and gonorrhoea, full blood count, C-reactive protein, faecal calprotectin when bowel symptoms.
• Transvaginal ultrasound (endometriosis, adenomyosis, fibroids, adnexal masses, hydrosalpinx), with MRI for deep endometriosis or adenomyosis.
• Pelvic venous imaging (duplex, CT or MR venography) for suspected pelvic venous disorder. Cystoscopy for suspected bladder pain syndrome. Colonoscopy for red flag bowel symptoms.
• Consider diagnostic laparoscopy when non-invasive assessment is unrevealing and the pain is severe or persistent, or when a lesion is suspected. It can allow treatment of endometriosis or adhesions. Do not use it simply to reassure when the examination and imaging are normal.
• Red flags requiring urgent evaluation: postmenopausal bleeding, weight loss, rectal bleeding, palpable mass, new onset after age 50.

Management is multimodal. It combines treatment of identified causes with pain management and psychological therapy, preferably in a multidisciplinary pain clinic.

• Education and explanation of the pain mechanisms (central sensitisation), setting realistic goals, and engagement with function focused rehabilitation.
• Analgesia: paracetamol 1 g every 6 hours and ibuprofen 400 mg every 8 hours or naproxen 500 mg every 12 hours (with food, for 5 to 7 day trials). Avoid long term opioids because of poor efficacy and harm.
• Neuromodulators: amitriptyline 10 mg at night, increased by 10 mg weekly to 50 to 75 mg (maximum 100 mg), or nortriptyline 10 to 75 mg.
• Duloxetine 30 mg daily increased to 60 mg after 1 to 2 weeks.
• Gabapentin 100 to 300 mg at night, increased gradually to 1,800 to 2,400 mg daily in three divided doses (evidence supports gabapentin for non-cyclical pain), or pregabalin 75 mg twice daily increasing to 150 mg twice daily.
• Review benefit at 6 to 12 weeks and stop if ineffective.
• Hormonal suppression for cyclical pain and suspected endometriosis: combined oral contraceptive continuous (ethinylestradiol 30 micrograms with levonorgestrel 150 micrograms), dienogest 2 mg daily, norethisterone 5 mg twice to three times daily, medroxyprogesterone depot 150 mg every 12 weeks, levonorgestrel intrauterine system, or GnRH agonist (goserelin 3.6 mg every 28 days for 3 to 6 months with add back therapy).
• Empirical hormonal therapy for 3 months is reasonable before laparoscopy.
• Pelvic floor physiotherapy for myofascial pain. In refractory cases add trigger point injections (lidocaine 1 percent, 5 to 10 mL; bupivacaine) or botulinum toxin 100 to 300 units in the pelvic floor muscles. Transcutaneous electrical nerve stimulation may also be used.
• Abdominal wall pain (anterior cutaneous nerve entrapment): local anaesthetic and corticosteroid injection (bupivacaine 0.25 percent 5 to 10 mL with triamcinolone 20 to 40 mg or methylprednisolone 40 mg) at the point of maximum tenderness.
• Psychological therapy: cognitive behavioural therapy, acceptance and commitment therapy, mindfulness based stress reduction, trauma focused therapy; sleep hygiene; graded exercise, yoga.
• Treat coexisting conditions:
  • Irritable bowel syndrome: dietary changes, antispasmodics, mebeverine 135 mg three times daily, peppermint oil, low FODMAP diet.
  • Bladder pain syndrome: bladder training, amitriptyline, pentosan polysulfate 100 mg three times daily, bladder instillations.
  • Constipation: macrogol.
  • Pelvic venous disorder: medroxyprogesterone, embolisation.
  • Endometriosis or adhesions: laparoscopic excision, adhesiolysis for dense adhesions with correlating pain.
• Surgical options for refractory pain: laparoscopic excision of endometriosis, presacral neurectomy (for midline pain, with risk of constipation and urinary dysfunction), and uterosacral nerve ablation (not recommended).
• Hysterectomy with or without salpingo oophorectomy is a last resort, when pelvic pathology is identified (adenomyosis, endometriosis) and childbearing is completed. Hysterectomy for pain with a normal pelvis relieves pain in only about 60 to 75 percent, and in 20 to 25 percent pain persists.
• Neuromodulation (sacral or pudendal), spinal cord stimulation and nerve blocks (superior hypogastric plexus, ganglion impar, pudendal nerve block) are options in pain clinics.
• Follow up: regular review, with the goal of function rather than pain elimination; relapses occur.