Hypothesis / aims of study
It is widely recognized that urinary incontinence is linked to a decrease in mental well-being (1). Urinary incontinence is a prevalent symptom during pregnancy and the postnatal period, often representing women's first encounter with it. Existing research indicates that UI might play a role in the development of depressive symptoms during the postpartum phase (2,3). The objectives of this systematic review and meta-analysis were to summarize the evidence regarding the relationship between urinary incontinence and postpartum depression and to assess whether the time after delivery influences the strength of the association
Study design, materials and methods
We present a systematic review with meta-analysis of cohort and cross-sectional studies. It was conducted according to the Cochrane Collaboration Handbook, and was reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and the MOOSE Reporting Guidelines for Meta-analyses of Observational Studies. The protocol was registered in the International Prospective Register of Systematic Reviews PROSPERO.
The PI(E)COs strategy was followed to determine the inclusion criteria: i) type of studies: cohort and cross-sectional studies; ii) participants: women in postpartum condition; iii) exposure: UI, defined as “involuntary loss of urine”, any type of UI determined through validated test or objective measured was considered; and iv) outcomes: PPD assessed by validated questionnaires. Studies that did not report the necessary information for the analyses were excluded.
Two reviewers independently conducted searches in databases including MEDLINE, Embase, Cochrane Library, Web of Science, and PsicINFO, covering the period from their inception to December 26th, 2023.
When at least two studies reported the effect estimate a meta-analysis was conducted considering the most adjusted effect estimates and their 95% confidence intervals (CI). We employed a DerSimonian and Laird random-effects model to calculate a pooled odds ratio (OR) and its corresponding 95% CI, as well as 95% prediction intervals, for the association between urinary incontinence and postpartum depression, according to the study design. Subgroup analyses were performed based on the time elapsed since delivery (< 6 months or ≥ 6 months), for this subgroup analysis only cohort studies were selected. The I2 statistic was used to examine the inconsistency, which ranges between 0 and 100%. Values of 0% - 40% were considered ‘not important’ heterogeneity, 30% to 60% ‘moderate’ heterogeneity, 50% to 90% ‘substantial’ heterogeneity, and 75% to 100% represented ‘considerable’ heterogeneity.The risk of bias was assessed using the NIH Quality Assessment Tool for Observational Cohort Studies. All statistical analyses were performed using StataSE v. 15 (StataCorp, College Station, TX, USA).
Results
The systematic searches identified a total of 465 studies, of which 141 duplicate records were removed. Finally, after the full-text review of the 22 studies assessed for eligibility, eleven studies were incorporated into the systematic review and meta-analysis (seven cohort studies and four cross-sectional studies) with a total of 92.974 participants. The time after delivery ranged from 25 days to 1 year. The overall odds ratio (OR) regarding the connection between urinary incontinence (UI) and postpartum depression (PPD) was 1.45, with a 95% confidence interval (CI) ranging from 1.11 to 1.79. The 95% prediction interval spanned from 0.49 to 2.40. The heterogeneity index (I2) was calculated at 65.9%, with a p-value of 0.001. The association between Urinary Incontinence and Postpartum Depression was analyzed by subgroups according to study type: Among the seven cohort studies, the OR stood at 1.63 (95% CI: 1.35 to 1.91), with a 95% prediction interval from 1.14 to 2.13, and an I2 of 11.1% (p = 0.345). For the four cross-sectional studies, the OR was 1.05 (95% CI: 1.04 to 1.05), with a 95% prediction interval from 1.04 to 1.06, and no observed heterogeneity (I2 = 0.0%, p = 0.413).
Regarding the duration post-delivery, the OR estimates for cohort studies with a postpartum period less than 6 months were 1.44 (95% CI: 1.07 to 1.81) with a prediction interval from 0.63 to 2.25, showing no heterogeneity (I2 = 0.0%, p = 0.603). Conversely, for those cohort studies with a postpartum period of 6 months or more, the OR was 1.53 (95% CI: 1.16 to 1.89), with a prediction interval from 0.41 to 2.65, and an observed heterogeneity of 50.7% (p = 0.087).
Interpretation of results
Our research represents the initial effort to consolidate the existing evidence concerning the link between urinary incontinence (UI) and postpartum depression (PPD). Our findings indicate that UI may elevate the likelihood of PPD by 45%. Moreover, assessments of the heightened risk of PPD among women experiencing postpartum UI from longitudinal studies did not significantly diverge from those derived from cross-sectional studies. Both the 95% prediction intervals consistently excluded the possibility of no effect and maintained the same trend as the 95% confidence interval. Ultimately, our analyses did not indicate any notable influence of the duration post-delivery on the risk of PPD among women dealing with postpartum UI.