Inclusion Criteria:

* Women who present with symptoms of OAB, defined as a condition characterized by urgency, with or without urgency incontinence, usually with frequency and nocturia in the absence of obvious pathology or infection \[9\], with atrophic vaginitis.
* Postmenopausal by history (i.e., defined as twelve months or greater since last menstrual period), surgical menopause with removal of bilateral ovaries, or age over 55 with a previous hysterectomy (without removal of bilateral ovaries).
* English language skills sufficient to complete questionnaires
* Clinical indication for vaginal estrogen use (i.e., hypoestrogenic findings on physical examination)
* Patients not currently receiving vaginal estrogen therapy

Exclusion Criteria:

* Patients currently on systemic hormone replacement therapy (HRT) or who have been on HRT within the past three months
* Patients with current diagnosis or history of estrogen dependent malignancies (e.g., breast or endometrial malignancies)
* Contraindication or allergy to estrogen therapy
* Insufficient English language skills to complete study questionnaires
* Women with active, standard culture positive urinary tract infection at baseline assessment, or those with a urine dip positive for leukocytes and nitrates on straight catheterized sample.
* Patients who have received antibiotics within the past two weeks
* Patients with stage 3 or 4 pelvic organ prolapse based on the pelvic organ prolapse quantitation system (POP-q)
* Patients unwilling to use vaginal estrogen preparation
* Patients currently on anticholinergic medications or who have received anticholinergic medications within the past three months
* Patients who have previously failed two medications for treatment of OAB or have previously received more advanced treatment for OAB including intra-vesicle botulinum toxin injections, posterior tibial nerve stimulation, or implantation of a sacral neuromodulator
* Patients wishing to start anticholinergic medication at the initial encounter
* Undiagnosed abnormal genital bleeding
* Active deep vein thrombosis (DVT), pulmonary embolism (PE), or a history of these conditions
* Active arterial thromboembolic disease (for example, stroke and MI), or a history of these conditions
* Known liver dysfunction or disease
* Known protein C, protein S, or antithrombin deficiency or other known thrombophilic disorders