Perinatal risk factors associated with acute kidney injury severity and duration among infants born extremely preterm

Background We evaluated time-varying perinatal risk factors associated with early (≤7 post-natal days) and late (>7 post-natal days) severe acute kidney injury (AKI) occurrence and duration. Methods A secondary analysis of Preterm Erythropoietin Neuroprotection Trial data. We defined severe AKI (stage 2 or 3) per neonatal modified Kidney Disease: Improving Global Outcomes criteria. Adjusted Cox proportional hazards models were conducted with exposures occurring at least 72 h before severe AKI. Adjusted negative binomial regression models were completed to evaluate risk factors for severe AKI duration. Results Of 923 participants, 2% had early severe AKI. In the adjusted model, gestational diabetes (adjusted HR (aHR) 5.4, 95% CI 1.1–25.8), non-steroidal anti-inflammatory drugs (NSAIDs) (aHR 3.2, 95% CI 1.0–9.8), and vancomycin (aHR 13.9, 95% CI 2.3–45.1) were associated with early severe AKI. Late severe AKI occurred in 22% of participants. Early severe AKI (aHR 2.5, 95% CI 1.1–5.4), sepsis (aHR 2.5, 95% CI 1.4–4.4), vasopressors (aHR 2.9, 95% CI 1.8–4.6), and diuretics (aHR 2.6, 95% CI 1.9–3.6) were associated with late severe AKI. Participants who had necrotizing enterocolitis or received NSAIDs had longer severe AKI duration. Conclusion We identified major risk factors for severe AKI that can be the focus of future research. Impact statement Time-dependent risk factors for severe acute kidney injury (AKI) and its duration are not well defined among infants born <28 weeks’ gestation. Over 1 in 5 infants born <28 weeks’ gestation experienced severe AKI, and this study identified several major time-dependent perinatal risk factors occurring within 72 h prior to severe AKI. This study can support efforts to develop risk stratification and clinical decision support to help mitigate modifiable risk factors to reduce severe AKI occurrence and duration.