ASSOCIATION BETWEEN ENLARGED GENITAL HIATUS AND PROLAPSE WITH OVERACTIVE BLADDER 1 YEAR AFTER VAGINAL DELIVERY.

BACKGROUND Genital hiatus enlargement is associated with pelvic organ prolapse and overactive bladder 5-10 years after first delivery. It is unknown if this association is present earlier postpartum. OBJECTIVE(S) To understand the association between overactive bladder within 1 year after first vaginal delivery and 1) enlarged genital hiatus, 2) anatomic pelvic organ prolapse, and 3) bulge symptoms. STUDY DESIGN This is a secondary analysis of a prospective cohort study of primiparous women with a singleton term vaginal delivery who completed symptom questionnaires and physical exams at the 3rd trimester, 8 weeks and 1 year postpartum. We defined overactive bladder as the presence of urinary urgency, plus urinary frequency or nocturia, or urgency incontinence on the Epidemiology of Prolapse and Incontinence Questionnaire. Enlarged genital hiatus was > 4 cm and anatomic pelvic organ prolapse was vaginal descent at or beyond the hymen. We evaluated associations of overactive bladder with genital hiatus, and pelvic organ prolapse at 1 year postpartum using Poisson regression. RESULTS We included 579 people with mean age of 29yo and 17% Hispanic. In separate models, enlarged genital hiatus and anatomic pelvic organ prolapse at 1 year postpartum were each associated with increased overactive bladder prevalence at 1 year postpartum (genital hiatus: adjusted risk ratio 1.5, 95% CI 1.1-2.1; pelvic organ prolapse: adjusted risk ratio 1.8, 95% CI 1.2-2.6). These effects were greater in women >30 years (genital hiatus: adjusted risk ratio 2.1, 95%CI 1.3-3.4; pelvic organ prolapse: adjusted risk ratio 2.2, 95% CI 1.3-3.7) and were not significant in women <30 years. CONCLUSION(S) Enlarged genital hiatus and pelvic organ prolapse at 1 year postpartum are associated with overactive bladder as early as 1 year postpartum, particularly in women >30 years. Genital hiatus may be a marker of pelvic floor function that, when impaired, increases the risk of pelvic organ prolapse and overactive bladder after delivery.