Modifiable Determinants of Urinary Incontinence During Pregnancy: A Systematic Review and Meta-Analysis of Adjusted Effect Estimates, with Updated Trimester-Specific Prevalence

Description Urinary incontinence (UI) is a common pelvic floor disorder during pregnancy, characterized by the involuntary leakage of urine. It represents an important maternal health concern because of its potential effects on physical functioning, psychological well-being, social participation, sleep, and overall quality of life. Pregnancy involves substantial anatomical, hormonal, mechanical, and physiological changes that may influence bladder function and pelvic floor integrity. Increasing uterine pressure, hormonal alterations, changes in connective tissue properties, and increased loading of the pelvic floor may contribute to the development or worsening of urinary incontinence throughout gestation. Although urinary incontinence is frequently experienced during pregnancy, its prevalence varies considerably across populations, study settings, diagnostic definitions, assessment instruments, and stages of pregnancy. The distribution of urinary incontinence across the first, second, and third trimesters is also inconsistent in the published literature. Furthermore, several demographic, reproductive, obstetric, lifestyle, and health-related characteristics have been investigated as potential determinants. However, the strength and consistency of their associations remain uncertain, particularly when findings are evaluated using multivariable-adjusted effect estimates that account for potential confounding factors. The purpose of this systematic review and meta-analysis is to comprehensively synthesize the available observational evidence on potentially modifiable determinants of urinary incontinence during pregnancy and to provide updated estimates of its prevalence across the three trimesters. Particular emphasis will be placed on adjusted effect estimates to identify associations that remain after accounting for relevant confounding variables. Potentially modifiable determinants will be distinguished from nonmodifiable demographic and reproductive characteristics to maintain a clear focus on factors that may inform preventive interventions and antenatal care strategies. The review will include observational studies involving pregnant women in any trimester and conducted in different geographical regions and healthcare settings. Eligible studies will report the prevalence of urinary incontinence, trimester-specific prevalence, or associations between relevant exposures and urinary incontinence. Studies reporting multivariable-adjusted odds ratios, risk ratios, prevalence ratios, hazard ratios, or other suitable adjusted association measures will be considered for the determinant analyses. Where appropriate, crude estimates will be summarized separately and will not be combined with adjusted estimates in the primary determinant meta-analysis. The literature search will cover relevant electronic databases, including PubMed/MEDLINE, Embase, Scopus, Web of Science, CINAHL, and other appropriate sources. Study selection, data extraction, and methodological quality assessment will follow established systematic review procedures. The methodological quality and risk of bias of included observational studies will be evaluated using an appropriate validated assessment tool. Where sufficient comparable studies are available, random-effects meta-analysis will be conducted to account for between-study variability. Statistical heterogeneity will be assessed using the I² statistic and other appropriate measures. Subgroup analyses will explore differences according to trimester, geographical region, study setting, urinary incontinence subtype, diagnostic method, and other relevant study characteristics, depending on the availability and comparability of the evidence. Sensitivity analyses will assess the robustness of pooled estimates. Publication bias and small-study effects will be evaluated when the number of contributing studies is sufficient. The certainty of evidence for the principal outcomes will be assessed using an appropriate evidence-grading framework. The primary expected outcome is an updated quantitative synthesis of potentially modifiable determinants of urinary incontinence during pregnancy based on multivariable-adjusted effect estimates. Secondary expected outcomes include pooled overall prevalence and separate prevalence estimates for the first, second, and third trimesters. Additional analyses will examine variations in prevalence and determinant associations across geographical regions, study populations, diagnostic approaches, and urinary incontinence subtypes. By distinguishing potentially modifiable determinants from nonmodifiable predictors and prioritizing adjusted associations, this review aims to provide clinically meaningful evidence that may help identify opportunities for prevention, early recognition, and targeted antenatal interventions. The findings are expected to inform maternal health professionals, obstetricians, midwives, pelvic floor rehabilitation practitioners, and researchers regarding the burden and potentially preventable contributors to urinary incontinence during pregnancy. The review will follow the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 reporting guideline. The protocol will be registered prospectively in the Open Science Framework (OSF) to promote transparency, reproducibility, and methodological accountability. The review will also document methodological limitations, differences in outcome definitions, and gaps in the available evidence to guide future research.