It is important to differentiate stress incontinence from other types of incontinence which may also be caused by different treatable gynaecological, urological or neurological illnesses.
Weight control, maintenance of pelvic floor muscle strength, abstaining from smoking, treatment of constipation as well as physical activity all prevent urinary incontinence.
Guided pelvic floor muscle training is used in the treament of mild and moderate urge incontinence.
For severe stress incontinence, mini-invasive suburethral sling procedures are applicable.
Urge incontinence may be treated with pharmacotherapy.
Topical oestrogen therapy, administered vaginally, alleviates the symptoms of urge incontinence in postmenopausal women.
Types of incontinence
In stress incontinence, involuntary loss of urine occurs during physical exertion or strain (e.g. coughing or sneezing), and it affects up to three quarters of adult patients who present with incontinence.
Urge incontinence is characterised by a sudden urge to urinate followed by involuntary loss of urine, either during the urge or immediately afterwards. It is typically seen in elderly post-menopausal women and also in young women. The detrusor muscle is hyperactive and hypersensitive.
Overactive bladder (OAB) is a contentious syndrome that is considered to consist of various combinations of urge to urinate and pollakiuria (> 8 voids per 24 hours) or nocturia (> 2 voids per night).
Mixed incontinence is a combination of the two above types. It is most common in women aged over 70 years.
Incomplete voiding and urinary retention, whether acute or chronic, may lead to overflow incontinence.
In epidemiological studies, the prevalence of female urinary incontinence in the adult population has ranged between 5% and 58% (median 28%). More than 50% of patients conceal the problem.
Approximately 6-7% of the population suffers from urinary incontinence of sufficient severity to interfere with their quality of life.
Urinary incontinence increases in frequency with age. Around 60% of women over 70 years of age suffer from it.
Aetiology
Stress incontinence is caused by weakness of the structures supporting the urethra or by sphincter insufficiency. The risk factors for stress incontinence include obesity (BMI > 25), pregnancy and giving birth as well as heavy smoking. Congenital connective tissue weakness may also be a risk factor for stress incontinence.
In urge incontinence bladder muscles contract inappropriately, the cause of which may be
non-neurogenic (acute or recurrent urinary tract infection, history of complicated urinary tract infections, tumour, disease affecting the bladder wall, bladder calculus, local oestrogen deficiency in postmenopausal women, fast bladder filling, diuretics, hysterectomy)
idiopathic; in approximately 80% of cases the cause remains unknown.
Overflow incontinence is caused either by impaired micturition reflex (e.g. a neurogenic aetiology, post surgery, a drug adverse effect) or by a mechanical obstruction (tumour, prolapse).
Investigations
History
In what situations does incontinence occur?
Standardised symptom questionnaires are suitable for clinical practice.
For how long has incontinence lasted?
Moderately severe urge incontinence with a fairly sudden onset may be suggestive of an organic aetiology, e.g. bladder disease, inflammation or pelvic tumour.
Severity?
How many times a week does the patient experience urinary incontinence, does she need to use protective pads and what impact does incontinence have on her life?
A frequency/volume chart is a simple tool for monitoring bladder function and the type and severity of incontinence.
Systemic illnesses and medication that may potentially affect bladder function (for example diuretics, anticholinergics, centrally acting analgesics, calcium channel blockers).
Clinical examination
General clinical examination: general health status, mobility, weight, neurological abnormalities.
Gynaecological examination: mucous membranes, prolapses, palpation to exclude tumours, cough stress test, digital assessment of the state of pelvic floor muscles, and measurement of residual urine Determining the Volume of Residual Urine by Ultrasonography in case of incomplete voiding (less than 150 ml is normal).
Laboratory investigations and imaging studies
In case of urge incontinence or mixed incontinence, urine chemistry, particle counting and culture should be carried out.
Occasional microscopic haematuria may be associated with physical exercise, menstruation, sexual intercourse or minor trauma.
Recurrent microscopic haematuria (see Haematuria; NB: a reagent strip test alone is not sufficient) warrants closer investigations.
Indications for a referral to specialist care
Haematuria or a suspicion of a bladder disease (difficulty urinating, pain associated with incontinence)
Residual urine volume more than 300 ml
Symptomatic prolapse
Pelvic tumour
Neurological problems
Troublesome incontinence that has already been treated with surgery
Suspicion of a fistula
Treatment-resistant urge incontinence
Severe stress incontinence, or if physiotherapy fails to provide adequate relief
Supervised regular pelvic floor muscle training of 2-6 months' duration is an effective form of therapy for stress incontinence, possibly also for other types of urinary incontinence Pelvic Floor Muscle Training for Urinary Incontinence in Women. Later, maintenance training should take place twice or thrice weekly.
Electrical stimulation of the tibial or pudendal nerve in order to reduce the overactivity of the bladder muscle as well as bladder training (deliberate increase of the time between emptying the bladder) may also be employed in urge incontinence Bladder Training for Urinary Incontinence.
Contraindications: urinary retention, uncontrolled narrow-angle glaucoma, myasthenia gravis, severe colitis.
Interactions must be borne in mind.
The most common adverse effects: dry mouth, blurred vision, postural hypotension, constipation and urinary retention. Moreover, the patient may experience central nervous system effects, such as cognitive disorders and confusion, which may be particularly troublesome in elderly patients.
The efficacy of the medication should be assessed at regular intervals (after about 2 months) because only a proportion of patients will benefit from the treatment and, on the other hand, if the adverse effects are only mild a dose increase may be attempted.
There is no difference in efficacy between the different agents. Adverse effect profiles are individual: try different preparations.
Beta-3 agonist mirabegronMirabegron for Urinary Incontinence and Overactive Bladder is without the salivary gland and gastrointestinal adverse effects typical of anticholinergic drugs. The regular dose is 50 mg orally once daily if the kidney and liver functions are normal. Mirabegron may raise blood pressure and cause tachycardia. Severe uncontrolled hypertension (systolic pressure ≥ 180 mmHg and/or diastolic pressure ≥ 110 mmHg), as well as prolonged QT interval are contraindications.
There are no significant differences in the efficacy of anticholinergic drugs and the beta-3 agonist.
Surgery is of no help in pure urge incontinence. In severe cases refractory to other treatments, injections of botulinum toxin A into the bladder wall have provided promising results.
Treatment can be performed in an outpatient setting by first applying local anaesthesia inside the bladder using lidocaine solution and then injecting the drug with an endoscopic needle inserted through a cystoscope.
Augmentation cystoplasty or a urinary stoma may be considered in extreme cases.
The treatment for mixed incontinence is chosen according to the dominant type of incontinence.
Incontinence protection
Vaginal cones and tampons prevent incontinence during short-lasting physical exercise.
Absorbent pads, pants and protective bedding will provide protection. In a persistent and severe incontinence the patient may be entitled to obtaining assistive devices and/or care supplies, such as pads or diapers, from public services. A trained incontinence nurse will be in charge of patient education and supplying incontinence products.
References
Cheater FM, Castleden CM. Epidemiology and classification of urinary incontinence. Baillieres Best Pract Res Clin Obstet Gynaecol 2000 Apr;14(2):183-205. [PubMed]
Bakas P, Papadakis E, Karachalios C et al. Assessment of the long-term outcome of TVT procedure for stress urinary incontinence in a female population: results at 17 years' follow-up. Int Urogynecol J 2019;30(2):265-269. [PubMed]
Apostolidis A, Dasgupta P, Denys P et al. Recommendations on the use of botulinum toxin in the treatment of lower urinary tract disorders and pelvic floor dysfunctions: a European consensus report. Eur Urol 2009;55(1):100-19. [PubMed]
Itkonen Freitas AM, Mentula M, Rahkola-Soisalo P et al. Tension-Free Vaginal Tape Surgery versus Polyacrylamide Hydrogel Injection for Primary Stress Urinary Incontinence: A Randomized Clinical Trial. J Urol 2020;203(2):372-378. [PubMed]