Multidrug-Resistant Urinary Tract Infections During Pregnancy: A Systematic Review of Epidemiology, Risk Factors and Maternal and Neonatal Outcomes

Urinary tract infections (UTIs) during pregnancy are increasingly complicated by antimicrobial resistance, potentially limiting therapeutic options and affecting maternal and neonatal outcomes. This systematic review synthesized the epidemiology, antimicrobial susceptibility patterns, associated risk factors, and clinical consequences of multidrug-resistant (MDR) UTIs during pregnancy. PubMed/MEDLINE, Embase, Scopus, and Web of Science were searched for studies published between January 2010 and July 2026. Seventy-nine studies involving 97,849 pregnant women were included. Gram-negative organisms accounted for 83.9% of microbial isolates, with Escherichia coli (52.7%) and Klebsiella pneumoniae (16.2%) predominating among isolated bacterial pathogens. MDR was reported in 41 studies, of which 28 applied standardized class-based definitions. Nine studies providing sufficiently comparable overall MDR estimates were included in a random-effects meta-analysis, yielding a pooled MDR proportion of 57.9% (95% CI 40.0–74.0%), with substantial heterogeneity (I2 = 95.2%) and a wide 95% prediction interval (12.3–93.1%). ESBL-producing uropathogens were reported in 38 studies. Among E. coli isolates, median study-level resistance was higher for ampicillin (75.0%) and trimethoprim–sulfamethoxazole (66.7%) and lower for nitrofurantoin (7.7%) and fosfomycin (1.9%). Previous antibiotic exposure was the most consistently reported factor associated with MDR infection. Resistance-stratified studies suggested a possible association between MDR and increased maternal infectious morbidity, whereas findings regarding adverse obstetric and neonatal outcomes were limited and inconsistent. Substantial heterogeneity in resistance definitions, study populations, and microbiological denominators limited the comparability and generalizability of MDR estimates across settings. Standardized surveillance and prospective resistance-stratified studies are needed to better characterize the clinical consequences of antimicrobial-resistant UTIs during pregnancy.