Urinary tract infections and risk of preterm birth: a systematic review and meta-analysis

Abstract

This systematic review and meta-analysis assessed the association between urinary tract infections (UTIs) during pregnancy and the risk of preterm birth (PTB). We searched multiple databases for relevant observational studies, categorizing them as UTI-based (comparing PTB incidence in women with and without UTIs) or PTB-based (comparing UTI prevalence in women with and without PTB). Using a random-effects model in Stata software version 17.0, we estimated pooled and adjusted odds ratios (ORs) with 95% confidence intervals (CIs), and performed subgroup, sensitivity, and cumulative analyses to explore heterogeneity. In total, 30 studies comprising 32 datasets were included, involving a total of 249,810 cases and 2,626,985 healthy controls. The meta-analysis revealed a significant positive association between UTIs during pregnancy and PTB occurrence (OR, 1.92; 95% CI, 1.62-2.27). A sub-group analysis based on studies, the participants showed significant association in both PTB-based (OR, 2.01; 95% CI, 1.58-2.56) and UTI-based studies (OR, 1.79; 95% CI, 1.42-2.26). However, Egger's test indicated the presence of publication bias (p=0.020), and substantial heterogeneity was observed across the included studies (I2=96.6; p< 0.001). These findings emphasize the critical importance of early detection and effective management of UTIs in pregnant women to reduce the risk of PTB and its associated adverse outcomes. While the results highlight a robust link between UTIs during pregnancy and PTB risk, the potential influence of publication bias and substantial heterogeneity should be considered to interpret these findings. Further research is needed to better understand the underlying mechanisms and to develop targeted interventions for high-risk pregnant women.

Figure 1. PRISMA flow diagram for study-selection for the meta-analysis.

Figure 2. Forest plots for overall meta-analysis of studies reporting effect of exposure to UTIs during pregnancy on risk of PTB.

Figure 3. Forest plots for overall meta-analysis of studies that reported adjusted odds ratios on effect of UTIs during pregnancy on risk of PTB.