Urinary Tract Infections in Pregnancy: A Review of Epidemiology, Risk Factors, and Maternal–fetal Outcomes

Urinary tract infections (UTIs) are among the most common medical complications observed in pregnancy and continue to be a significant contributor to morbidity in mothers and newborns globally. The physiological and immunological alterations that occur in pregnancy make women prone to urinary stasis and subsequent ascending bacterial infections, leading to a wide spectrum of disease from asymptomatic bacteriuria to acute cystitis and potentially life-threatening pyelonephritis. Globally, asymptomatic bacteriuria has been observed to affect 2-10% of pregnant women, and acute pyelonephritis complicates 2% of pregnancies, which is a significant cause of non-obstetric hospitalization during pregnancy.1-3 Asymptomatic bacteriuria, if untreated, can lead to symptomatic infection. This review aims to compile the current body of evidence regarding the epidemiology, microbiology, risk factors, and maternal and fetal outcomes of UTIs during pregnancy. Escherichia coli is still the main causative organism, although the emergence of antimicrobial resistance, including extended-spectrum beta-lactamase-producing organisms, has made empirical therapy more challenging.4,5 Established risk factors include recurrent urinary tract infections, diabetes mellitus, parity, low socioeconomic status, and lack of access to antenatal care.6,7 Maternal morbidities associated with untreated or suboptimally managed UTIs include anemia, hypertensive disorders, sepsis, and acute kidney injury, while those in the fetus include preterm birth, low birth weight, intrauterine growth restriction, and admission to the neonatal intensive care unit.8-10 Screening for asymptomatic bacteriuria, prompt diagnosis with urine culture, and effective antimicrobial treatment are critical in preventing complications. This review emphasizes the role of antenatal screening and antimicrobial use in improving outcomes, especially in resource-poor countries where the disease burden remains high.11,12