Effect of Interpregnancy Interval on the Development of Pelvic Floor Disorders

Importance The effect of a short interpregnancy interval (IPI) on pelvic floor disorders is unknown. Objectives We investigated the relationship between a short IPI and the development of stress incontinence (SUI), pelvic organ prolapse (POP), and anal incontinence (AI) in the decade after the first delivery. Study Design We performed a secondary analysis of the Mothers’ Outcomes After Delivery study—a prospective cohort of women recruited 5–10 years following their first delivery and followed annually between 2008 and 2018. A short IPI was defined as ≤18 months, calculated as the number of months between deliveries minus the length of the second pregnancy. SUI, POP, and AI were identified by annual validated questionnaires, examination, or history of treatment. Data were analyzed in SAS. Variables significant on bivariate analysis were entered into multivariable logistic regression models predicting each outcome using the generalized estimating equations approach for repeated measures. Results Of 1,127 women, the majority (671, 59%) never had a short IPI, 395 (35%) had 1 short IPI, and 61 (6%) had 2 or more. Within 10–15 years, 219 women (19%) reported SUI, 156 (14%) reported POP, and 251 (22%) reported AI. We found that a short IPI was not associated with SUI ( P =0.69), POP ( P =0.71), or AI ( P =0.95). When restricting the cohort to women with only nonoperative vaginal deliveries (n=440), there remained no difference in the presence of SUI, POP, or AI ( P = 0.88, 0.84, 0.78, respectively). Conclusions A short IPI is not associated with pelvic floor disorders in the decade following the first delivery. This should be reassuring to women at risk of PFDs who elect to become pregnant within 18 months of childbirth.