Is there an association between parity and urinary incontinence in women during pregnancy and the first year postpartum?: A systematic review and meta-analysis

Aims To systematically review the literature on possible associations between parity and urinary incontinence (UI) during pregnancy and in the first year postpartum. Methods We searched the databases Pubmed, CINAHL, Embase, the Cochrane Library, PsycINFO, MIDIRS, (inception-18 April 2020). One reviewer screened all titles. Two reviewers independently selected studies by abstract and full text. Risk of bias was assessed using the Quality In Prognosis Studies tool. Findings were synthesised in meta-analysis or narratively. We assessed the certainty of evidence using the Grading of Recommendations, Assessment, Development and Evaluation Working Group approach adopted for prognostic studies. Results We identified 16 643 records and 39 were included. Thirty studies examined UI during pregnancy and 12 examined UI postpartum. Multiparity was associated with UI at any point in the last pregnancy (odds ratio [OR]: 1.59 [1.26-2.00], 5 studies, 1565 participants) and in the third trimester when measured by ICIQ-SF (OR: 2.67 [1.53-4.67], 4 studies, 1150 participants), but not when studies measured the UI point prevalence (OR: 2.48 [0.91-6.79], 4 studies, 52 976 participants), or if they measured the prevalence at one point in any trimester (OR: 1.09 (0.60-1.95), 3 studies, 872 participants). At 3 months postpartum, UI was associated with multiparity (OR: 2.03 [1.35-3.06], 4 studies, 6781 participants). Conclusions Increased parity was associated with UI in the first year postpartum, but studies on UI during pregnancy had conflicting results. The evidence was (very) uncertain. Future studies should use comparable definitions and further explore UI sub-types.