From Gestational Age–Specific Serum Creatinine Trajectories to an Interactive Clinical Interpretation Tool in Level IV NICU Infants

Objective To characterize gestational age (GA)-specific serum creatinine (SCr) trajectories among level IV neonatal intensive care unit (NICU) infants and develop an interactive interpretation tool. Study Design We analyzed ADVANCE database records linking kidney-specific data with Children's Hospitals Neonatal Consortium clinical data from ten level IV NICUs (2010–2022). Infants with ≥ 1 SCr measurement (DOL 1-365) were included. GA-specific trajectories were generated for DOL 1–28 and week of life 1–16; an interactive tool was developed for clinical use. Result Among 34,306 infants contributing 390,612 SCr measurements, SCr trajectories differed by GA. Peak SCr ranged from 0.93 mg/dL (IQR 0.80–1.10) at 22–24 weeks' GA (DOL 4) to 0.76 mg/dL (IQR 0.65–0.90) among term infants (DOL 2), declining to a similar nadir (~ 0.20–0.23 mg/dL) across GA groups. Conclusion SCr trajectories vary by GA and postnatal age in this population. These trajectories and the accompanying tool provide context for interpreting SCr values.