Why Stress Urinary Incontinence Can Worsen as Hormones Change

For many women, stress urinary incontinence — leaking urine with a cough, sneeze, or jump — becomes noticeable for the first time as oestrogen begins to decline. This happens during perimenopause and continues into menopause. It isn't coincidence, and it isn't simply about getting older. There is a direct hormonal mechanism at work, and it centres on a concept called urethral closure pressure.

What is urethral closure pressure?

Under normal conditions, the pressure inside the urethra — the short tube through which urine passes out of the body — is higher than the pressure inside the bladder. This pressure difference is what keeps urine in.

Urethral closure pressure is the difference between those two pressures. As long as it remains positive, the urethra stays closed.

When you cough, sneeze, jump, or lift, the pressure inside your abdomen rises suddenly. That rise transfers to the bladder. For continence to be maintained, the urethra needs to either match or exceed that pressure spike — it needs to stay closed.

Several structures contribute to this:

• The pelvic floor muscles, which help to create a firm support behind the urethra so that pressure can compress it closed (covered in detail in our post on what causes SUI)

• The connective tissue surrounding and supporting the urethra and bladder neck

• The urethral mucosa — the lining of the urethra — which forms a mucosal seal when healthy and well-hydrated

• The vascular cushion inside the urethra — a layer of blood vessels that contributes to the urethra sealing closed from the inside

• The smooth muscle within the urethral wall itself

When all of these are functioning well, the urethra can maintain closure even under significant load. When one or more of these layers is compromised, urethral closure pressure falls — and the risk of leaking with exertion increases.

Where does oestrogen fit in?

Oestrogen receptors have been identified in the urethral epithelium, urethral sphincter, bladder trigone, vaginal fascia, and the levator ani muscles of the pelvic floor (Blakeman et al., 1996; Gebhart et al., 2001). Oestrogen is not simply a reproductive hormone — it is an active maintenance signal for the tissue layers that contributes to urethral closure pressure.

Specifically, oestrogen:

• Keeps the urethral mucosa thick, supple, and well-hydrated, supporting the mucosal seal

• Maintains the vascular cushion inside the urethra

• Drives collagen synthesis and turnover in the connective tissue that supports the bladder neck and urethra

• Helps maintain smooth muscle tone within the urethral wall

Together, these effects keep baseline urethral closure pressure within a range that can manage everyday loads — including sudden increases in intra-abdominal pressure (Robinson & Cardozo, 2011; Cody et al., 2012).

What happens when oestrogen reduces?

As oestrogen levels fall during perimenopause and into menopause, each of the tissue layers described above is affected.

The urethral mucosa thins and loses its lubrication. The vascular cushion reduces. Collagen content in the connective tissue supporting the urethra and bladder neck begins to decline. One study of postmenopausal women found a statistically significant positive correlation between skin collagen content and maximum urethral closure pressure — suggesting that oestrogen-related collagen changes have a direct and measurable effect on how well the urethra can stay closed under load (Fantl et al., 1994).

Circulating oestrogen can fall by up to 90% at menopause (Robinson & Cardozo, 2011). The combined effect of these tissue changes is a reduction in baseline urethral closure pressure. The urethra simply has less capacity to maintain its seal when intra-abdominal pressure rises.

This is why SUI can appear for the first time, or worsen, during this stage of life — even in women who have had no previous bladder symptoms.

Does this mean SUI is inevitable as oestrogen declines?

No.

The hormonal layer is one contributing factor. It interacts with others that vary between women — pelvic floor muscle strength, the integrity of connective tissue support, birth history, body weight, and how much load is being placed on the system. Some women move through this life stage with no change to their continence. Others notice leaking for the first time. Others find that symptoms they already had become harder to manage.

What this means practically

If SUI has appeared or worsened during perimenopause or menopause, there are two distinct areas to consider:

The muscular and structural layer — this is where pelvic floor physiotherapy can help. Pelvic floor muscle training is the first-line treatment for stress urinary incontinence, with strong evidence for reducing leak frequency and severity (Dumoulin et al., 2018). Improving pelvic floor strength and the timing of muscle activation under load directly addresses the support and pressure mechanisms described above.

The hormonal and tissue layer — low-dose vaginal oestrogen applied topically has evidence for improving urethral and vaginal tissue health in women with reduced oestrogen (Cody et al., 2012). This is a conversation to have with your GP or gynaecologist — but it's worth raising alongside any physiotherapy treatment if you're at this life stage and experiencing bladder symptoms.

How we support bladder health at Balanced Physiotherapy & Pilates

At our women's health physiotherapy clinic in Vincentia, we see many women who notice bladder changes for the first time as their hormones shift. A physiotherapy assessment includes a thorough history, pelvic floor muscle evaluation, and an individualised rehabilitation plan — addressing the muscular, coordination, and load management components of SUI.

If you're noticing changes to your bladder, this is worth addressing — not just working around.

References

Blakeman, P. J., Hilton, P., & Bulmer, J. N. (1996). Oestrogen and progesterone receptor expression in the female lower urinary tract, with reference to oestrogen status. British Journal of Urology, 77(4), 542–548. https://doi.org/10.1046/j.1464-410X.1996.93239.x

Cody, J. D., Jacobs, M. L., Richardson, K., Moehrer, B., & Hextall, A. (2012). Oestrogen therapy for urinary incontinence in post-menopausal women. Cochrane Database of Systematic Reviews, 10, CD001405. https://doi.org/10.1002/14651858.CD001405.pub3

Dumoulin, C., Cacciari, L. P., & Hay-Smith, E. J. C. (2018). Pelvic floor muscle training versus no treatment, or inactive control treatments, for urinary incontinence in women. Cochrane Database of Systematic Reviews, 10, CD005654. https://doi.org/10.1002/14651858.CD005654.pub4

Fantl, J. A., Cardozo, L., & McClish, D. K. (1994). Estrogen therapy in the management of urinary incontinence in postmenopausal women: A meta-analysis. Obstetrics & Gynecology, 83(1), 12–18.

Gebhart, J. B., Rickard, D. J., Barrett, T. J., Lesnick, T. G., Webb, M. J., Podratz, K. C., & Spelsberg, T. C. (2001). Expression of estrogen receptor isoforms alpha and beta messenger RNA in vaginal tissue of premenopausal and postmenopausal women. American Journal of Obstetrics and Gynecology, 185(6), 1325–1331. https://doi.org/10.1067/mob.2001.117690

Robinson, D., & Cardozo, L. (2011). Estrogens and the lower urinary tract. Neurourology and Urodynamics, 30(5), 754–757. https://doi.org/10.1002/nau.21106