Estrogen for Urinary Incontinence
Systemic oral estrogen therapy (with or without progestin) should NOT be used to treat urinary incontinence in postmenopausal women, as it worsens incontinence rather than improving it. However, topical vaginal estrogen may provide benefit for certain types of incontinence and should be considered as a treatment option in postmenopausal women with urogenital atrophy.
Route of Administration Matters Critically
Systemic Oral Estrogen: Harmful for Incontinence
Oral estrogen alone increases the risk of developing new-onset urinary incontinence (stress, urge, or mixed types) with a hazard ratio of 1.53 (95% CI 1.37-1.71) after just 1 year of treatment in previously continent women 1.
Combined oral estrogen plus progestin similarly worsens incontinence with a hazard ratio of 1.39 (95% CI 1.27-1.52) for new-onset incontinence 1.
In women who already have incontinence, systemic hormone therapy worsens symptoms: 39% of women on combined hormones experienced worsening compared to 27% on placebo, while only 21% improved on hormones versus 26% on placebo (p=0.001) 2.
These negative effects persist: incontinence symptoms continued for at least 3 years of follow-up in women taking estrogen plus progestin 1.
The U.S. Preventive Services Task Force explicitly states that systemic hormone therapy is associated with increased incidence of stress, mixed, or any urinary incontinence in previously asymptomatic postmenopausal women 1.
Topical Vaginal Estrogen: Potentially Beneficial
Topical vaginal estrogen (intravaginal tablets, creams, or ovules) may improve stress incontinence compared to placebo, with a risk ratio of 0.74 (95% CI 0.64-0.86) 1, 3.
Meta-analyses demonstrate that vaginal estrogen prevents recurrent UTIs in postmenopausal women and may reduce urinary frequency and urgency by approximately 1-2 fewer voids per 24 hours 1, 3.
The mechanism involves restoring vaginal pH, reducing gram-negative bacterial colonization, and promoting lactobacillus-dominant vaginal flora 1.
Important caveat: Transdermal estrogen patches have been shown to worsen both stress and any urinary incontinence, so the benefit appears specific to intravaginal administration 1.
Clinical Algorithm for Estrogen Use in Urinary Incontinence
For Postmenopausal Women WITH Urinary Incontinence:
Do NOT prescribe systemic oral estrogen (with or without progestin) for incontinence treatment 1, 2.
Consider topical vaginal estrogen (creams, tablets, or pessaries) if:
Prioritize pelvic floor muscle training (PFMT) over estrogen: one trial showed women were 2.3 times more likely to improve with PFMT than with local estrogen (RR 2.30,95% CI 1.50-3.52) 3.
For Postmenopausal Women WITHOUT Incontinence:
- Avoid systemic hormone replacement therapy if incontinence prevention is a concern: large trials show it increases the risk of developing new incontinence 1.
Safety Considerations
Vaginal estrogen does NOT increase serum estrogen levels and is not associated with increased risk of breast cancer recurrence, endometrial hyperplasia, or endometrial carcinoma 1.
Common side effects of vaginal estrogen include vaginal spotting, breast tenderness, or nausea, though serious adverse events are rare 3.
Long-term systemic estrogen use carries significant risks including stroke (HR 1.34-1.36), DVT (HR 1.47-1.88), pulmonary embolism, gallbladder disease, and dementia 1.
The FDA black box warning mandates that systemic estrogen should be prescribed at the lowest effective dose for the shortest duration 1.
Key Pitfalls to Avoid
Do not assume all estrogen formulations work the same way: systemic oral estrogen harms incontinence while topical vaginal estrogen may help 1.
Do not prescribe transdermal estrogen patches for incontinence: these worsen symptoms similar to oral formulations 1.
Do not rely on estrogen as monotherapy: combination with alpha-adrenergic agonists (like phenylpropanolamine) may be more effective than estrogen alone for stress incontinence 5, 4.
Recognize that evidence for vaginal estrogen comes from trials with limited long-term follow-up: there is insufficient data on effects after treatment discontinuation 3.