Prevalence and spectrum of infections among women with gestational diabetes mellitus: a systematic review and meta-analysis

Infections are a potentially preventable cause of maternal morbidity. Yet their frequency among women with gestational diabetes mellitus (GDM) remains unclear because published studies have examined different infection sites, clinical settings, and diagnostic methods. We estimated prevalence by infection category and examined sources of study-level variation. We searched five electronic databases from inception to 28 February 2026 for observational studies that reported infections among women with GDM. Proportions were pooled on the logit scale using random-effects models with restricted maximum likelihood estimation and modified Hartung–Knapp confidence intervals. We also assessed prediction intervals, meta-regression results, sensitivity analyses, and certainty of evidence. Twenty-five studies involving 7,156 women were included in the review. Pooled prevalence was 16.8% for urinary tract infection (UTI) (95% confidence interval [CI] 7.4%–33.7%; 95% prediction interval 1.4%–74.7%). It was 22.8% for genital tract infection (95% CI 12.6%–37.5%; 95% prediction interval 3.4%–71.5%). The three periodontal studies were summarized narratively. Heterogeneity was substantial (I² = 95.0%–96.7%), and certainty was low for both pooled outcomes. Exploratory meta-regression showed that larger studies reported lower prevalence (coefficient − 0.809; 95% CI − 1.281 to − 0.337; P = 0.001), although residual heterogeneity remained high (I² = 96.3%). This review provides category-specific estimates and an evidence map for infection research in women with GDM. Wide prediction intervals show that the estimates must be applied in the context of the infection category and clinical setting. Standard definitions and multicenter cohorts are needed to obtain more precise estimates for clinical practice. Not applicable.