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 chi(2) 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.