By Dr. Shreya Patel
Stress incontinence is defined as “involuntary loss of urine upon effort or physical exertion, sneezing, or coughing”, and is essentially due to insufficient strength of the pelvic floor muscles.1 If you have been diagnosed with it, or believe you are affected by it, you are definitely not alone — it is the most common type of urinary incontinence between the ages of 20 and 50 years.2 Depending on age, the prevalence is between 29% and 75%, with a mean of 48%.3
Stress incontinence occurs due to weakened muscles of the pelvic floor. Established risk factors for stress urinary incontinence include pregnancy and childbirth, specifically those women who delivered vaginally. Having had a higher number of pregnancies increases this risk and it is thought that incontinence is linked to injury to the muscles and nerves of the pelvic floor during pregnancy and childbirth.4
Another risk factor is having a hysterectomy. The pelvic floor muscles can be damaged or weakened during hysterectomy, although the exact mechanism is not understood very well.5 Stress incontinence has also been associated with prolapse of the uterus, rectum or bladder, high body mass index and having a chronic cough.6 The latter two place pressure on the pelvic floor over long periods of time, which can lead to weakening of the muscles.
The symptoms associated with stress incontinence are leakage of urine when pressure is placed on the bladder during activity. Examples include sneezing, coughing, lifting, or during exercise. The leakage can range from a few drops to a stream of urine.
The link between menopause and stress incontinence
The menopause is the absence of menstrual periods for 12 months and marks the time when ovarian function decreases. However, this does not happen suddenly and one of the characteristics of menopause is the decline of the hormone oestrogen. During menopause, the ovary has reduced sensitivity to follicle stimulating hormone and luteinising hormone – the hormones required for developing follicles and ovulation. It is the follicle (once stimulated by these hormones) that produces oestrogen. As there is a reduction (and eventually cessation) in menstrual cycles during the menopause, oestrogen levels fall.
The lower part of the urinary tract, which includes the bladder, urethra, and pelvic floor muscles, is lined with oestrogen receptors (sensors which respond to oestrogen). Oestrogen appears to have a role in the urinary tract, as when women are oestrogen deficient, as seen during the menopause, symptoms such as urinary frequency and incontinence are prevalent. 70% of women have related the onset of urinary incontinence to their final menstrual period.7
The term urogenital atrophy is used to describe what happens to the urinary tract and reproductive tract during low levels of oestrogen. This essentially means wasting away of muscle mass in the vagina and the urinary tract. Oestrogen has a role in the quality and quantity of collagen in these areas, the supportive structure around the bladder, and blood flow.8 This means that during menopause, a time when oestrogen levels are low, all the above are affected, and this results in changes to the urinary system which leads to urinary incontinence.
Stress incontinence is at its peak prevalence around the time of menopause, but then declines following the menopause. It is seen more frequently between the ages of 41 and 55 years, and declines after that.9 The prevalence of stress incontinence as mentioned earlier can be as high as 75% which suggests that this is a very common problem.
The reason there is such a large range in terms of prevalence is because women do not report their symptoms to their doctors, and so it is likely that the prevalence of stress incontinence is actually underestimated.
What can you do to help reduce stress incontinence symptoms?
Many treatments are available for stress incontinence, including lifestyle modifications. For example, losing weight if you are overweight to reduce the pressure on pelvic floor muscles. Cutting back on caffeine, alcohol, and reducing fluid intake if you already drink large amounts, can all help reduce leakage.
You can also try doing pelvic muscle exercises, including Kegel exercises, to strengthen the pelvic floor muscles. These exercises need to be done on a regular basis, and your GP can refer you to nurses or physical therapists that can assist you with these to ensure you are doing them properly. There is substantial evidence showing pelvic floor exercises lead to a better quality of life, and women report fewer leakage episodes per day.10
Another potential treatment is topical vaginal oestrogen, creams that can be applied to the urogenital area that work on the oestrogen receptors in this region. Oestrogen subjectively improves stress incontinence but given in combination with phenylpropanolamine is more effective.11 Phenylpropanolamine is a medication that acts on the muscle around the urethra to increase its tone.
The evidence surrounding oral hormone replacement therapy is mixed when it comes to urinary incontinence. Cochrane (an organisation that reviews and organises medical research findings to facilitate evidence based choices) has found that trials looking at oral (systemic) oestrogen and incontinence show that women report worsening of their urinary symptoms.12
However, if you are experiencing other menopause symptoms then it may be that oral hormone replacement therapy is better for you. It is important to discuss the risks and benefits of each medication with your doctor to ensure you get the optimum treatment for you personally.
Vaginal pessaries can also reduce stress incontinence. These are flexible silicone rings that are inserted into the vagina to help support the muscles that hold up the bladder and uterus. Once fitted, it should not cause any discomfort.
Finally, there are various surgeries available for stress incontinence including injections, a urethral sling, and colposuspension. They are all designed to increase the supportive structure around the bladder and urethra. Each surgery comes with its own risks and benefits, and need to be discussed with a urogynaecologist to determine which surgery is most appropriate. Age, lifestyle, and general health plays an important role when making decisions about surgery and medication.
If you are experiencing symptoms of stress incontinence, please see your doctor. It is a very common problem and there are ways in which your quality of life can be improved.