Obstetric anal sphincter injuries (OASIS) cause significant morbidity and are well known risk factors for sexual dysfunction, urinary and anal incontinence. Postpartum and breastfeeding are relative hypoestrogenic states with risk factors for dyspareunia and vaginal atrophy. Estrogen deficiency results in changes in the vaginal epithelium and poor tissue quality which results in poor wound healing. For postmenopausal women with vaginal atrophy undergoing surgery for pelvic organ prolapse, early administration of topical vaginal E2 therapy resulted in improved markers of tissue quality. Currently, there are limited studies to reference for proposed treatment modalities to improve sexual function and incontinence in this population. In this proposed randomized, placebo-controlled trial, women who sustain OASIS will be recruited and randomized to begin intravaginal estrogen therapy or placebo at their 2-week follow-up visit after hospital discharge. Participants will complete validated questionnaires relating to sexual function and pelvic floor disorders (urinary and anal incontinence) symptom distress and impact. The primary outcome of this study will be sexual dysfunction symptom severity measured by the female sexual function index (FSFI) at 6 months postpartum. Secondary outcomes will be urinary and anal incontinence distress and impact measured by St. Mark's score and the fecal incontinence quality of life (FIQOL) questionnaire for anal incontinence and urogenital distress inventory (UDI-6) for urinary incontinence. The objective of this study is to determine if intra-vaginal estrogen therapy improves sexual function and incontinence symptom distress and impact for postpartum women after OASIS.