Obstetric anal sphincter injuries (OASIS) are known to cause significant morbidity and are known risk factors for sexual dysfunction, urinary and anal incontinence. Recent studies have reported that women with OASIS experience more problems with sexual dysfunction compared to their age and parity matched counterparts who do not have these tears. Despite this, little attention is paid to its prevalence or treatment in this population. These women are also at a 4-fold higher risk of anal incontinence. Additionally, significantly more women with OASIS report urinary incontinence 10 weeks after delivery and have significantly worse quality of life scores. 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.

Due to the significant morbidity associated with OASIS, it is critical to further explore treatment options to ultimately improve wound healing and outcomes in women who sustain OASIS tears in their postpartum recovery. Training in identification of OASIS and close follow up in specialized OASIS clinics have improved outcomes for these women. However, there are limited studies to reference for proposed treatment modalities to improve sexual function and incontinence in this population. Intra-vaginal estrogen therapy has proven to be safe and feasible in this population as demonstrated by no difference in the serum estrogen concentration in those women treated with intra-vaginal estrogen therapy for treatment of granulation tissue. Although evidence is limited, anecdotally, vaginal estrogen cream has been used to treat postpartum women with OASIS to treat vaginal atrophy and improve wound healing. This proposed research is critical to ultimately improving the postpartum recovery for women who sustain OASIS. This information will add to the growing literature aiming to optimize quality of life and improve care for these women.

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, (upon establishing care at postpartum perineal clinic), after hospital discharge. Participants will complete validated questionnaires relating to sexual function and pelvic floor disorders (urinary and anal incontinence) symptom distress and impact at the 2-week postpartum visit (baseline). Participants will follow up at designated intervals (12-weeks and 6 months) and complete questionnaires with plan for total of 6-months intravaginal estrogen or placebo therapy. The primary outcome 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 and the fecal incontinence quality of life (FIQOL) scores 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. We hypothesize that topical vaginal estrogen cream therapy postpartum will improve sexual function scores thereby improving functional status and related quality of life.