Association between enlarged genital hiatus and prolapse with overactive bladder 1 year after vaginal delivery

Abstract

Background

Genital hiatus enlargement is associated with pelvic organ prolapse and overactive bladder 5 to 10 years after first delivery. It is unknown if this association is present earlier postpartum.

Objective

This study aimed 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 examinations at the third trimester and 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 defined as ≥4 cm, and anatomic pelvic organ prolapse was defined as 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 a mean age of 29 years; 17% were 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% confidence interval, 1.1–2.1; pelvic organ prolapse: adjusted risk ratio, 1.8; 95% confidence interval, 1.2–2.6). These effects were greater among women aged ≥30 years (genital hiatus: adjusted risk ratio, 2.1; 95% confidence interval, 1.3–3.4; pelvic organ prolapse: adjusted risk ratio, 2.2; 95% confidence interval, 1.3–3.7) and were not significant among women aged <30 years.

Conclusion

Enlarged genital hiatus and pelvic organ prolapse at 1 year postpartum are associated with overactive bladder at as early as 1 year postpartum, particularly among women aged ≥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.