No increased risk of adverse pregnancy outcomes in women with urinary tract infections: A nationwide population-based study

Objective. To examine the risk of adverse pregnancy outcomes (low birthweight (LBW), preterm birth, and small-for-gestational age (SGA)) in pregnant women with urinary tract infections (UTIs) using a 3-year nationwide population-based database, simultaneously taking characteristics of infant and mother into consideration. Design. Retrospective cross-sectional study. Setting. Taiwan. Sample. In total, 42,742 mothers with UTIs and 42,742 randomly selected mothers were included. Methods. Conditional logistic regression analyses to investigate the risk of LBW, preterm birth, and SGA, comparing these two cohorts. Main outcome measures. LBW, preterm birth, and SGA. Results. Pearson χ² tests show that there were significant differences in the prevalence of preterm births (<37 weeks) (7.2%, 7.7 vs. 8.3%, p 0.006) and SGA infants (<10th percentile) (16.1%, 16.5 vs. 18.9%, p 0.003) among pregnant women who were not exposed to UTIs, those exposed to antepartum non-pyelonephritic UTIs and those exposed to pyelonephritis. However, after adjusting for potential confounding factors, the odd ratios (ORs) for LBW were not statistically significant for mothers exposed to antepartum non-pyelonephritic UTIs, compared to women who were not diagnosed with UTIs; neither for <34 or <37 weeks nor SGA <10th percentile and <2 SDs. Similarly, compared to women who were not exposed to UTIs, the adjusted ORs for LBW, <34 weeks, <37 weeks, SGA <10th centile, and <2 SD did not reach a significant level for mothers exposed to pyelonephritis. Conclusions. Women exposed to antepartum pyelonephritis or non-pyelonephritic UTIs were not at increased risk of having LBW, preterm, and SGA babies, compared to mothers who did not experience UTIs.