Clinical History
It is essential to start by taking a detailed medical history. The nature, frequency and site of the pain, and its relationship to precipitating factors and the menstrual cycle, may provide vital clues to the aetiology. A detailed menstrual and sexual history, including any history of sexually transmitted diseases and vaginal discharge is mandatory. Tactful inquiry about previous sexual trauma may be appropriate.
Clinical Examination
Abdominal and pelvic examination will exclude any gross pelvic pathology (tumours, scarring and reduced uterine mobility), as well as demonstrating the site of tenderness if present. Abnormalities in muscle function should also be sought.
Investigations
Vaginal and endocervical swabs to exclude infection are mandatory and cervical cytology screening is advisable. Pelvic ultrasound scanning provides further information about pelvic anatomy and pathology. Laparoscopy is the most useful invasive investigation to exclude gynaecological pathology and to assist in the differential diagnosis.
Dysmenorrhoea
Primary dysmenorrhoea classically begins at the onset of ovulatory menstrual cycles and tends to decrease following childbirth. Explanation and reassurance may be helpful, together with the use of simple analgesics progressing to the use of non-steroidal anti-inflammatory drugs (NSAIDs), which are particularly helpful if they are started before the onset of menstruation. NSAIDs are effective in dysmenorrhoea probably because of their effects on prostaglandin synthetase. Suppression of ovulation using the oral contraceptive pill reduces dysmenorrhoea dramatically in most cases and may be used as a therapeutic test. Because of the chronic nature of the condition, potentially addictive analgesics should be avoided.
Secondary dysmenorrhoea suggests the development of a pathological process and it is essential to exclude endometriosis and pelvic infection.
Infection
A history of possible exposure to infection should be sought and it is mandatory in all cases to obtain swabs to exclude chlamydia and gonorrhoea, as well as vaginal and genital tract pathogens. Patient's sexual contacts need to be traced in all cases with a positive culture. If there is any doubt about the diagnosis, laparoscopy may be very helpful.
Primary herpes simplex infection may present with severe pain, associated with an ulcerating lesion and inflammation, which may lead to urinary retention. Hospitalization and opiates may be needed to achieve adequate analgesia.
Treatment
Treatment of infection depends on the causative organisms. Subclinical chlamydial infection may lead to tubal pathology. Screening for this organism in sexually active young women may reduce the incidence of subsequent subfertility.
Endometriosis
The condition may be suspected from a history of secondary dysmenorrhoea and often dyspareunia, as well as the finding of scarring in the vaginal fornices on vaginal examination, with reduced uterine mobility and adnexal masses. Laparoscopy is the most useful diagnostic tool.
Endometriotic lesions affecting the urinary bladder or causing ureteric obstructions can occur, as well as lesions affecting the bowel, which may lead to rectal bleeding in association with menstruation.
Treatment
As in primary dysmenorrhoea, analgesics and NSAIDs are helpful in easing pain at the time of menstruation. Hormone treatment with progestogens or the oral contraceptive pill may halt progress of endometriosis, but is not curative. A temporary respite may be obtained by using luteinizing hormone releasing hormone (LHRH) analogues to create an artificial menopause, though the resulting oestrogen deficiency may have marked long-term side effects, such as reduced bone density and osteoporosis in those taking more than six months worth of treatment. These drugs are used prior to surgery to improve surgical outcome and reduce surgical complications.
Surgery for endometriosis is challenging and the extensive removal of all endometriotic lesions is essential. The best results are achieved laparoscopically, by highly trained and skilled laparoscopic surgeons, in specialist centres. A multidisciplinary team will be required for the treatment of extensive disease, including a pain management team.
The pain associated with endometriosis is often not proportionate to the extent of the condition and, even after extensive removal of the lesions and suppression of the condition, the pain may continue.
Gynaecological Malignancy
The spread of gynaecological malignancy of the cervix, uterine body or ovary will cause pelvic pain depending on the site of spread. Treatment is of the primary condition, but all physicians dealing with pelvic pain must be fully aware of the possibility of gynaecological malignancy.
Injuries Related to Childbirth
Tissue trauma and soft tissue injuries occurring at the time of childbirth may lead to chronic pelvic pain related to the site of injury. Dyspareunia is a common problem leading to long-term difficulties with intercourse and female sexual dysfunction. Denervation of the pelvic floor with re-innervation may also lead to dysfunction and pain. Hypo-oestrogenism, as a result of breast feeding, may also contribute to pelvic floor pain and dysfunction.
Post-menopausal oestrogen deficiency may lead to pain associated with intercourse, which will respond to hormone replacement therapy.
Conclusion
Once all the above conditions have been excluded, the gynaecologist may well be left with patients with unexplained pelvic pain. It is imperative to consider pain associated with the urinary and gastrointestinal tract at the same time. For example, patients with bladder pain quite often present with dyspareunia due to bladder base tenderness.
Previously, pelvic congestion has been cited as a course of pelvic pain of unknown aetiology, but this diagnosis is not universally recognised.
As previously stated in dealing with pelvic pain, the best results will be obtained from a multidisciplinary approach that considers all possible causes.
