Chapter 103: Lower abdominal and pelvic pain in women

Pain in the lower abdomen and pelvis is one of the most frequent symptoms experienced by women. The diagnostic approach requires a wide variety of consultative skills, especially when the pain is chronic. The examination of acute abdominal pain has been simplified by sensitive serum pregnancy tests, ultrasound investigation and laparoscopy. However, an accurate history and examination for all types of pain will generally pinpoint the diagnosis. The ever-present problem of PID, the leading cause of infertility in women, demands an early diagnosis and appropriate management.

A summary of the diagnostic strategy model is presented in TABLE 103.1.

Probability diagnosis

The commonest causes are primary dysmenorrhoea, the pain of a ruptured Graafian follicle (mittelschmerz), endometriosis and adhesions. In many instances of pain no diagnosis is made as no pathological cause can be found.

Serious disorders not to be missed

The potentially lethal problem of a ruptured ectopic pregnancy must not be missed, hence the axiom ‘be ectopic minded’. PID can be overlooked, especially if chronic, and requires early diagnosis and aggressive treatment. Neoplasia must be considered, especially malignancy of pelvic structures, including the ‘silent’ ovarian cancer.

Pitfalls

Several disorders are very difficult to diagnose and these include haemorrhage into the ovary or a cyst, torsion of the ovary or pedunculated fibroid. Endometriosis may be missed so it is important to be familiar with its symptoms. Chronic constipation may be a trap.

Seven masquerades checklist

Two important conditions to consider are urinary tract infection and spinal dysfunction. Just as disorders of the pelvic organs, such as endometriosis and PID, can refer pain to the low back and buttocks, so can disorders of the lumbosacral spine cause referred pain to the lower abdomen and groin.

Psychogenic considerations

These can be extremely relevant. Problems in the patient’s social, marital or sexual relationships should be evaluated, especially in the assessment of chronic pain. Patients with chronic pelvic pain may have experienced difficulties in personal development, relationships, sexual confidence, educational and financial opportunities. Such issues can have implications for medical management and need to be handled with sensitivity and tact.⁴

History

The pain should be linked with the menstrual history, coitus and the possibility of an early pregnancy. For recurrent and chronic pain, it is advisable to instruct the patient to keep a diary over two menstrual cycles. The severity of the pain can be assessed as follows:²

• does not interfere with daily activity

• results in days off work

• results in confinement to bed

In this way the pain can be classified objectively as mild, moderate or severe.

The typical pain patterns in relation to menstruation are shown in FIGURE 103.1.

Examination

One objective is to correlate any palpable tenderness with the patient’s statement of the severity of the pain. Use the traditional abdominal and pelvic examination to identify the site of tenderness and rebound tenderness, and any abdominal or pelvic masses. The pelvis should be examined by speculum (preferably bivalve type) and bimanual palpation.

Proper assessment can be difficult if the patient cannot relax, if there is abdominal scarring or obesity, or if extreme tenderness is present. It is therefore important, especially in the younger and apprehensive patient, to conduct a gentle, caring vaginal examination with appropriate explanation and reassurance. Explanation of the procedure during vaginal examination, preferably using eye contact with the patient, can help her relax and be more confident in the procedure.

Investigations

Investigations may be selected from:

• haemoglobin level

• white blood cell count (limited value)

• haematocrit

• ESR/CRP

• microbiology (limited value):

  • – urine for microscopy and culture ± Chlamydia PCR

  • – endocervical and vaginal swabs

• serum β-hCG assay

• urinary hCG tests (can be negative in the presence of an ectopic pregnancy)

Diagnostic imaging:

• vaginal ultrasound—to define a gestation sac

• pelvic ultrasound—to differentiate a cystic from a solid pelvic mass. Indicated for:

  • – pelvic pain

  • – a palpable pelvic mass

  • – a palpable lower abdominal mass

  • – ascites

Laparoscopy is indicated if the history and examination are suggestive of ectopic pregnancy and ultrasound fails to confirm an intra-uterine pregnancy.

The causes of acute pain are summarised in TABLE 103.2. The patient is usually young (20–30 years old), sexually active and distressed by the pain, and should be considered foremost to have a bleeding ectopic pregnancy. Important differential diagnoses include acute PID, rupture or torsion of an ovarian cyst and acute appendicitis. Cases of acute ruptured ectopics are obviously easier to diagnose in the presence of circulatory collapse.

Chronic pelvic pain is constant or recurrent pain of at least 6 months’ duration.

Features

• Incidence 15% in 18–50-year-olds

• Endometriosis causes 33%, adhesions 24%

• It is the reason for up to 40% of gynaecological laparoscopies

• Reason for 15% of hysterectomies

The pain can be cyclical (e.g. endometriosis, mittelschmerz) or continuous.

The common causes of chronic pain are listed in TABLE 103.3. Chronic pain is more difficult to diagnose and it is often difficult to differentiate between problems such as endometriosis, PID, an ovarian neoplasm and the irritable bowel syndrome. A comparison of the clinical features of endometriosis and PID is presented in TABLE 103.4. Furthermore it is difficult to distinguish clinically between endometriosis of the uterus (adenomyosis) and pelvic congestion syndrome. Both conditions are associated with dysmenorrhoea and a tender normal-sized uterus.

Ectopic pregnancy

Ectopic pregnancy occurs approximately once in every 100 clinically recognised pregnancies. If ruptured it can be a rapid, fatal condition so we have to be ‘ectopic minded’. It is the commonest cause of intraperitoneal haemorrhage. There is usually a history of a missed period but a normal menstrual history may be obtained in some instances.

Clinical features of a ruptured ectopic pregnancy

• Average patient in mid-20s

• First pregnancy in one-third of patients

• Patient at risk

  • – previous ectopic pregnancy

  • – previous PID

  • – previous abdominal or pelvic surgery, especially sterilisation reversal

  • – IUCD use

  • – in-vitro fertilisation

• Pre-rupture symptoms (many cases):

  • – abnormal pregnancy

  • – cramping pains in one or other iliac fossa

  • – vaginal bleeding

• Rupture:

  • – excruciating pain (see FIG. 103.2)

  • – circulatory collapse

    Note: In 10–15% there is no abnormal bleeding.

• Pain may radiate to rectum (lavatory sign), vagina or leg

• Signs of pregnancy (e.g. enlarged breasts and uterus) usually not present

Examination

• Deep tenderness in iliac fossa

• Vaginal examination:

  • – tenderness on bimanual pelvic examination (pain on cervical provocation, i.e. cervical motion tenderness)

  • – palpable adenxal mass

  • – soft cervix

• Bleeding (prune juice appearance)

• Temperature and pulse usually normal early

Diagnosis⁵

It is possible to diagnose ectopic pregnancy at a very early stage of pregnancy.

• Urine pregnancy test (positive in most ectopics)

• Serum β-hCG assay—may need serial quantitative tests to distinguish an ectopic from a normal intra-uterine pregnancy (IUP). If it is >2000 IU/L an IUP should be visible on vaginal ultrasound. If the uterus is empty, ectopic is more likely. If <2000 IU/L, repeat every second day to see if it is increasing normally as expected in a normal IUP.

• Transvaginal ultrasound can diagnose at 5–6 weeks (empty uterus, tubal sac, fluid in cul-de-sac)

• Laparoscopy (the definitive diagnostic procedure)

Management

Possible options are surgery, medical or watchful expectancy. Treatment may be conservative (based on ultrasound and β-hCG assays); medical, by injecting intramuscular methotrexate; laparoscopic removal; or laparotomy for severe cases. Rupture with blood loss (usually about 7% of cases⁶) demands urgent surgery. Organise blood and contacts, resuscitate as necessary.

• Successful pregnancy 60–65%

• Subsequent risk of ectopic pregnancy 10–15%

Ruptured ovarian (Graafian) follicle (mittelschmerz)

When the Graafian follicle ruptures a small amount of blood mixed with follicular fluid is usually released into the pouch of Douglas. This may cause peritonism (mittelschmerz), which is different from the unilateral pain experienced just before ovulation due to distension of the ovarian capsule.

Clinical features

• Onset of pain in mid-cycle

• Deep pain in one or other iliac fossa (RIF > LIF)

• Often described as a ‘horse kick pain’

• Pain tends to move centrally (see FIG. 103.3)

• Heavy feeling in pelvis

• Relieved by sitting or supporting lower abdomen

• Pain lasts from a few minutes to hours (average 5 hours)

• Patient otherwise well

Note: Sometimes it can mimic acute appendicitis.

Management

• Explanation and reassurance

• Simple analgesics: aspirin or paracetamol

• ‘Hot water bottle’ comfort if pain severe

Benign ovarian tumours, particularly ovarian cysts, may be asymptomatic but will cause pain if complicated. They are common in women under 50 years of age. Ovarian cysts are best defined by vaginal ultrasound, which can identify whether haemorrhage has occurred inside or outside the cyst.

Symptoms

• Pain (usually torsion or haemorrhage)

• Pressure symptoms

• Menstrual irregularity

Ruptured ovarian cyst

The cysts tend to rupture just prior to ovulation or following coitus.

Clinical features

• Patient usually 15–25 years

• Sudden onset of pain in one or other iliac fossa

• May be nausea and vomiting

• No systemic signs

• Pain usually settles within a few hours

Signs

• Tenderness and guarding in iliac fossa

• PR: tenderness in rectovaginal pouch

Investigation

• Pelvic ultrasound (transvaginal and transabdominal views)

Management

• Appropriate explanation and reassurance

• Conservative:

  • – simple cyst <4 cm

  • – internal haemorrhage

  • – minimal pain

• Needle vaginal drainage by ultrasonography for a simple larger cyst

• Laparoscopic surgery:

  • – complex cysts

  • – large cysts

  • – external bleeding

Acute torsion of ovarian cyst

Torsions are mainly from dermoid cysts and, when right-sided, may be difficult to distinguish from acute pelvic appendicitis.

Clinical features

• Severe cramping lower abdominal pain (see FIG. 103.4)

• Diffuse pain

• Pain may radiate to the flank, back or thigh

• Repeated vomiting

• Exquisite pelvic tenderness

• Patient looks ill

Signs

• Smooth, rounded, mobile mass palpable in abdomen

• May be tenderness and guarding over the mass, especially if leakage

Diagnosis

• Pelvic ultrasound

Treatment

• Laparoscopy and surgical correction

Malignant ovarian tumours

Ovarian cancer has an incidence of 10 cases per 10 000 women per year and accounts for 5% of all cancers in women and 20% of all gynaecological cancers. It is responsible for more gynaecological cancer deaths because the tumour is often well advanced at the time of clinical presentation. Earlier discovery may sometimes be made on routine examination or because of investigation of non-specific pelvic symptoms.

Ovarian cancer tends to remain asymptomatic for a long period. No age group is spared but it becomes progressively more common after 45 years (peak incidence 60–65 years) (see CHAPTER 26).

The familial causes and relationship to breast and colorectal cancer are being delineated. Refer to CHAPTER 18.

Risk factors

• Age

• Family history

• Nulliparity

• BRCA1 and BRCA 2 gene mutations

• Ashkenazi Jewish ancestry

Protective factors

• COC pill

• Pregnancy

Clinical features

• Constitutional symptoms: fatigue, anorexia

• Ache or discomfort in lower abdomen or pelvis

• Abdominal bloating and ‘fullness’

• Gastrointestinal dysfunction (e.g. epigastric discomfort, diarrhoea, constipation, wind)

• Sensation of pelvic heaviness

• Genitourinary symptoms (e.g. frequency, urgency, prolapse)

• ± Abnormal uterine bleeding

• Postmenopausal bleeding

• Dyspareunia and/or dysmenorrhoea (10–20%)

• ± Weight loss

• A bimanual examination assists diagnosis. Look for mass, ascites, pleural effusion

A pelvic mass plus ascites usually indicates ovarian cancer but occasionally may be caused by a benign ovarian fibroma (Meigs’ syndrome—a triad of benign ovarian tumour + ascites + pleural effusion).

Note: Any ovary that is easily palpable is usually abnormal (normal ovary rarely >4 cm).

Diagnosis

• Pelvic ultrasound with transvaginal and transabdominal views

• Tumour markers such as CA-125, β-hCG (choriocarcinoma), human epididymis protein 4 (HE4) and alpha-fetoprotein should be measured only if the ultrasound raises suspicion of malignancy⁷

Refer urgently to gynaecologist. Treatment is usually laparoscopy ± adjuvant chemotherapy.

Dysmenorrhoea (painful periods) may commence with the onset of the menses (menarche) when it is called primary dysmenorrhoea, or later in life when the term secondary dysmenorrhoea is applied.

Primary (functional) dysmenorrhoea

This is menstrual pain associated with ovular cycles without any pathologic findings. The pain usually commences within 1–2 years after the menarche and becomes less severe with age. It affects about 50% of menstruating women and up to 95% of adolescents.

Clinical features

• Low midline abdominal pain

• Pain radiates to back or thighs (see FIG. 103.5)

• Varies from a dull dragging to a severe cramping pain

• Maximum pain at beginning of the period

• May commence up to 12 hours before the menses appear

• Usually lasts 24 hours but may persist for 2–3 days

• May be associated with nausea and vomiting, headache, syncope or flushing

• No abnormal findings on examination

Management

• Full explanation and appropriate reassurance

• Promote a healthy lifestyle:

  • – regular exercise

  • – avoid smoking and excessive alcohol

• Recommend relaxation techniques such as yoga

• Avoid exposure to extreme cold

• Place a hot water bottle over the painful area and curl the knees onto the chest

Medication

Options include (trying in order):

• simple analgesics (e.g. aspirin or paracetamol)

• NSAIDs

  • – naproxen 500 mg (o) initially then 250 mg every 6—8 hours (max 1250 mg/day)

  • – or ibuprofen 200–400 mg (o) tds (max 1600 mg/day)

  • – commence at first suggestion of pain in the first 3 days of the period (if simple analgesics ineffective)

• combined oral contraceptive pill

• progestogen-medicated IUCD

If not helped by these treatments, further investigation is required.

A Cochrane review found that the most beneficial medication was the NSAIDs, and vitamin B1 and magnesium also proved effective. There is no evidence so far that vitamin B6, vitamin E or herbal remedies are effective. Spinal manipulation is unlikely to be beneficial.⁸

Secondary dysmenorrhoea

Secondary dysmenorrhoea is menstrual pain for which an organic cause can be found. It usually begins after the menarche following years of pain-free menses; the patient is usually over 30 years of age. The pain begins as a dull pelvic ache 3–4 days before the menses and becomes more severe during menstruation.

Commonest causes:

• endometriosis (a major cause)

• PID (a major cause)

• IUCD (copper)

• submucous myoma

• intra-uterine polyp

• pelvic adhesions

Investigations

Investigations include laparoscopy, ultrasound and (less commonly) assessment of the uterine cavity by dilation and curettage, hysteroscopy or hysterosalpingography.

Management involves treating the cause.

Pelvic adhesions

Pelvic adhesions may be the cause of pelvic pain, infertility, dysmenorrhoea and intestinal pain. They can be diagnosed and removed laparoscopically when the adhesions are well visualised and there are no intestinal loops firmly stuck together.

Endometriosis

Endometriosis is the condition where ectopically located endometrial tissue (usually in dependent parts of the pelvis and in the ovaries) responds to female sex hormone stimulation by proliferation, haemorrhage, adhesions and ultimately dense scar tissue changes. The average time to diagnosis is 10 years. The diagnosis is masked by taking NSAIDs and the COC.

Patients experience varying degrees of symptoms and loss of gynaecological function according to the site and severity of the endometriosis deposits. Pregnancy is beneficial but recurrence can follow.

Clinical features⁹

• 5–10% incidence

• Puberty to menopause, peak 25–35 years

• Secondary dysmenorrhoea

• Painful defecation during menses

• Urinary symptoms; dysuria, frequency

• Pain may radiate to lower back, legs or rectum

• Subfertility

• Dyspareunia

• Non-specific pelvic pain

• Menorrhagia

• Acute pain with rupture of endometrioma

• Premenstrual spotting

Possible signs

• Fixed uterine retroversion

• Tenderness and nodularity in the pouch of Douglas/retrovaginal septum

• Uterine enlargement and tenderness

Adenomyosis: this is endometriosis of the myometrium affecting the endometrial glands and stroma. The symptoms are similar to endometriosis plus an enlarging tender uterus.

Differential diagnosis

• PID—see TABLE 103.4

• Ovarian cysts or tumours

• Uterine myomas

• Irritable bowel syndrome (a common misdiagnosis)

Diagnosis

• Usually by direct visual inspection at laparoscopy (the gold standard)

• Transvaginal ultrasound (usefulness not well established, may identify ovarian endometrioma or rectal endometriosis)

• Curettage (not routinely performed) shows small sensory C nerve fibres in the endometrium

Treatment

• Careful explanation

• NSAIDs (first line), can be supplemented by paracetamol

• Treatment can be surgical or medical

  Medical:¹⁰ To induce amenorrhoea (only two-thirds respond to drugs):

  • – COC: once daily continuously—long term

  • – levonorgestrel-releasing IUCD (Mirena) 5-yearly and indefinite

  • – progestogens (e.g. medroxyprogesterone acetate—Depo-Provera) or orally 10 mg bd for up to 6 months

  • – GnRH analogues, e.g. goserelin, 3.6 mg SC implant every 28 days for up to 6 months, nafarelin (limited by adverse effects)

Surgical: Surgical measures depend on the patient’s age, symptoms and family planning. Laser surgery, diathermy ablation and excision of endometriomata can be performed via laparoscopy. When endometriosis is associated with infertility, laparoscopic surgery is preferred to drug therapy.

Pelvic inflammatory disease

There are great medical problems in the serious consequences of PID, namely tubal obstruction, infertility and ectopic pregnancy. PID may be either acute, which causes sudden severe symptoms, or chronic, which can gradually produce milder symptoms or follow an acute episode. Acute PID is a major public health problem and is the most important complication of STIs among young women. The majority are young (less than 25 years), sexually active women who are also nulliparous. PID is usually polymicrobial, caused by sexually acquired pathogens and/or vaginal flora.¹¹

Some patients may experience no symptoms but others may have symptoms that vary from mild to very severe. The clinical diagnosis can be difficult as signs and symptoms can be nonspecific and correlate poorly with the extent of the inflammation.

Clinical features

• Fever ≥38°C

• Moderate to severe lower abdominal pain

• Ache in the lower back

• Mild lower abdominal pain

• Dyspareunia

• Menstrual problems (e.g. painful, heavy or irregular periods)

• Intermenstrual bleeding

• Abnormal, perhaps offensive, purulent vaginal discharge

• Painful or frequent urination

The diagnostic criteria for acute PID are presented in TABLE 103.5.

Examination

• In acute PID there may be lower abdominal tenderness ± rigidity.

• Pelvic examination: in acute PID there is unusual vaginal warmth, cervical motion tenderness and adnexal tenderness. Speculum examination usually reveals a red inflamed cervix and a purulent discharge.

Causative agents

These can be subdivided into three broad groups:

1. Exogenous organisms: those which are community acquired and initiated by sexual activity. They include the classic STIs, Chlamydia trachomatis (the most common causative organism) and Neisseria gonorrhoeae. This usually leads to salpingitis.

2. Endogenous infections: these are normal commensals of the lower genital tract, especially Escherichia coli and Bacteroides fragilis. They become pathogenic under conditions that interrupt the normal cervical barrier, such as recent genital tract manipulation or trauma (e.g. abortion, presence of an IUCD, recent pregnancy or a dilatation and curettage). The commonest portals of entry are cervical lacerations and the placental site. These organisms cause an ascending infection and can spread direct or via lymphatics to the broad ligament, causing pelvic cellulitis (see FIG. 103.6).

3. Actinomycosis: very rare cause of a chronic polymicrobial inflammatory mass that can mimic pelvic malignancy. Due to prolonged IUCD use. Look for Actinomyces israelii on culture if suspected and seek expert advice.

Investigations

Diagnosis is clinical. A definitive diagnosis is difficult since routine specimen collection has limitations in assessing the organisms. Definitive diagnosis is by laparoscopy but this is not practical in all cases of suspected PID.

• Endocervical swabs for NAAT (e.g. PCR) N. gonorrhoeae, C. trachomatis and M. genitalium

• Endocervical swab for culture

• Blood culture if febrile

• Pelvic ultrasound to detect alternative causes of pain

Treatment

Note: Any IUCD should be removed if there is no response to treatment in 48 to 72 hours. A new IUCD can be inserted once the infection has resolved. Current sexual partners should be treated with agents effective against C. trachomatis (and N. gonorrhoeae if likely), irrespective of test results.

Mild to moderate infection (treated as an outpatient):

• ceftriaxone 500 mg (in 2 ml 1% lignocaine) IM or 500 mg IV, as a single dose (for gonorrhoea)

• plus

• metronidazole 400 mg (o) 12 hourly for 14 days

• plus

• doxycycline 100 mg (o) 12 hourly for 14 days

Severe infection (treated in hospital):

• ceftriaxone 2 g IV daily or cefotaxime 2g IV tds

• plus

• azithromycin 500 mg IV daily

• plus

• metronidazole 500 mg IV 12 hourly until there is substantial clinical improvement, when the oral regimen above can be used for the remainder of the 14 days

Mild to moderate infection:

• amoxycillin + clavulanate (875 mg/125 mg) (o) 12 hourly for 14 days

• plus

• doxycycline 100 mg (o) 12 hourly for 14 days

Severe infection (including septicaemia):

• amoxy/ampicillin 2 g IV 6 hourly

• plus

• gentamicin 4–6 mg/kg IV for 1 dose, then 1 or 2 further doses based on renal function

• plus

• metronidazole 500 mg IV 12 hourly

• All cases of ‘unexplained infertility’

• All teenagers with dysmenorrhoea sufficient to interfere with normal school, work or recreational activities, and not responding to prostaglandin inhibitors

• Patients with dysmenorrhoea reaching a crescendo mid-menses

• Patients with dysmenorrhoea and unexplained bowel or bladder symptoms

• Patients with positional dyspareunia

• Patients with cyclic pain or bleeding in unusual sites

Note: Pelvic disease that can be treated by advanced laparoscopy surgery includes ectopic pregnancy, ovarian cysts, endometriosis and endometriomas, fibromyomata, pelvic adhesions and hydrosalpinx.

Hand-out sheets from Murtagh’s Patient Education 7th edition:

• Dysmenorrhoea (painful periods)

• Endometriosis

• Pelvic inflammatory disease