IMPACT OF ANEMIA ON THE CLINICAL COURSE OF GESTATIONAL PYELONEPHRITIS

Abstract

Gestational pyelonephritis remains one of the most serious non-obstetric infections during pregnancy and is associated with substantial maternal and fetal morbidity. Concurrent anemia, which is highly prevalent among pregnant women, may significantly worsen the clinical course of this condition by impairing oxygen delivery, altering immune function, and increasing susceptibility to systemic inflammatory complications. This review analyzes current evidence regarding the influence of maternal anemia on gestational pyelonephritis, with emphasis on pathophysiological mechanisms, maternal outcomes, obstetric consequences, and therapeutic implications. Recent large-scale cohort studies have demonstrated that pregnant patients with both pyelonephritis and anemia experience significantly higher rates of severe maternal morbidity, sepsis, acute respiratory distress syndrome, shock, and acute kidney injury compared with non-anemic counterparts. In a nationwide United States study, severe maternal morbidity occurred in 27.8% of anemic patients versus 8.9% of non-anemic patients, with an adjusted relative risk of 2.86. Anemia also independently increases the risk of preterm birth and prolongs hospitalization. These findings underscore the need for early recognition and correction of anemia as an integral component of prenatal care and inpatient management. Optimizing hemoglobin levels before and during pregnancy may represent a modifiable strategy to reduce infectious and obstetric complications.