Vitamin D and stress urinary incontinence in pregnancy: a cross-sectional study.

To assess the association between levels of vitamin D and urinary incontinence (UI) in pregnancy.

A cross-sectional study. Secondary analysis of a randomised controlled trial. Setting Two university hospitals in Norway. Population 851 healthy, pregnant women >18 years in gestational week 18-22 with a singleton live fetus.

Data on UI were collected from a questionnaire at inclusion and serum analysis of 25-hydroxy vitamin D (25(OH)D) was performed. Univariable and multivariable logistic regression analyses were applied to study associations between exposure and outcomes. Main Outcome Measures Prevalence of self-reported UI, stress (SUI) and urge (UUI) or mixed UI.

In total 230/851 (27%) of the participants were vitamin D insufficient (25(OH)D <50nmol/L) and 42% reported to have any UI. Women with 25(OH)D <50nmol/L were more likely to report any UI (p=0.03) and SUI (p<0.01) compared to women with 25(OH)D ≥50nmol/L. In a univariable logistic regression analysis, serum levels of 25(OH)D <50nmol/L was associated with increased risk of any UI (Odds Ratio, OR 1.5 with 95% Confidence interval CI (1.0, 2.1)), SUI only (OR 1.7 (1.2, 2.4)), but not mixed UI or UUI only (OR 0.8 (0.5,1.5)). In a multivariable logistic regression model, serum levels of 25(OH)D <50nmol/L was associated with a higher risk of experiencing SUI only (OR 1.5 (1.1,2.2)).

Serum 25(OH)D <50nmol/L was associated with increased risk of any UI and SUI in particular.

BJOG : an international journal of obstetrics and gynaecology. 2020 Jun 01 [Epub ahead of print]

Signe Nilssen Stafne, Siv Mørkved, Miriam K Gustafsson, Unni Syversen, Astrid Kamilla Stunes, Kjell Åsmund Salvesen, Hege Hølmo Johannessen

Department of Public Health and Nursing, Norwegian University of Science and Technology (NTNU), P.O. Box 8905, 7491, Trondheim, Norway., Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology (NTNU), P.O. Box 8905, 7491, Trondheim, Norway., Department of Obstetrics and Gynecology, St. Olavs Hospital, Trondheim University Hospital, P.O. Box 3250 Sluppen, 7006, Trondheim, Norway., Department for Physical Medicine and Rehabilitation, Østfold Hospital Trust, Sarpsborg, Norway.