- Enter the reference (lowest previous) serum creatinine in mg/dL. In neonates, the reference SCr is the lowest prior SCr — not a pre-illness baseline — because neonatal SCr falls during the first 1–2 weeks of life as the maternal contribution clears.
- Enter the current serum creatinine in mg/dL. The SCr ratio, absolute rise, and SCr-based stage update automatically.
- Optionally enter the urine output (mL/kg/hr) averaged over the assessment window (default 24 h). UO-based stage updates as well.
- Gestational age (weeks) and postnatal age (days) are optional context fields — they do not alter the stage calculation but help frame the SCr trajectory.
- The final AKI stage = worst of the SCr-based and UO-based stages. Tick the dialysis box to force stage 3.
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When to Use
Use the modified neonatal KDIGO definition to detect and stage AKI in any neonate (term or preterm, in the NICU or post-discharge) with risk factors or evolving renal dysfunction. The classification is the standard for both clinical care and research (Jetton/AWAKEN) and combines a serum-creatinine criterion with a urine-output criterion, taking the worst-of the two as the final stage.
Appropriate population
Neonates (≤28 days of postnatal age; many centres extend through the NICU stay) with risk factors for AKI — perinatal asphyxia / hypoxic-ischemic encephalopathy, sepsis, necrotizing enterocolitis (NEC), nephrotoxin exposure (aminoglycosides, vancomycin, NSAIDs, IV contrast, amphotericin), congenital anomalies of the kidney and urinary tract (CAKUT), maternal hypertension or hypotension, prematurity, congenital heart disease, ECMO, and post-cardiac-surgery.
When NOT to rely on it as-is
The classification assumes a usable "lowest previous" SCr; in the first 24–48 h of life that value may still reflect maternal creatinine and the trajectory has not yet declined — interpret with caution and re-evaluate as serial SCr values become available. Preterm SCr stays higher longer than term, so birth-weight-specific trajectories are essential context. Anuria/oliguria in the first 24 h after birth may be physiological (delayed first void) rather than AKI. UO criteria require a reliable timed urine collection (catheter, weighed diaper) — estimated voids are unreliable.
Pearls & Pitfalls
Reference SCr = lowest previous, not pre-illness baseline
The single most important departure from adult/pediatric KDIGO: in a neonate, the "baseline" SCr is the lowest measured SCr to date, not a pre-illness value. Neonatal SCr drops over the first 1–2 weeks as the maternal contribution clears and the neonate's own GFR matures, so the lowest previous SCr is the most meaningful denominator. Stage 3 also carries an absolute SCr threshold of ≥ 2.5 mg/dL (lower than adult thresholds) because neonatal baselines are themselves low.
Worst-of SCr OR UO
SCr-based stage and UO-based stage are calculated independently and the higher of the two is the final AKI stage. A neonate can be stage 3 by UO criterion (≤ 0.3 mL/kg/hr × ≥ 24 h) with a still-falling SCr — both deserve recognition and trigger nephrotoxin review and management. Receipt of dialysis automatically classifies as stage 3.
Pitfalls
(1) Using a single SCr value in isolation — the diagnosis requires comparison with the lowest previous. (2) Anchoring on birth SCr in the first 24–48 h, when it still reflects maternal creatinine. (3) Ignoring UO because "diapers were not weighed" — UO criteria need timed collection. (4) Forgetting that creatinine generation in tiny preterm infants is small, so even modest SCr rises (≥ 0.3 mg/dL within 48 h) are clinically significant. (5) Neonatal AKI is common (~30% of critically ill NICU admissions in AWAKEN) and is under-recognized — it is associated with mortality and future CKD, so do not dismiss "borderline" rises.
Why Use It
Neonatal AKI is common — roughly 30% of critically ill NICU admissions meet criteria in the AWAKEN cohort — and is independently associated with longer hospital stay, increased mortality, and progression to chronic kidney disease. Yet it remains under-recognized because clinicians schooled in adult/pediatric KDIGO often compare neonatal SCr to a "normal adult" baseline, miss the post-birth decline, and fail to capture early injury. The modified neonatal KDIGO definition (Jetton/AWAKEN) anchors the comparison to the lowest previous SCr and lowers the absolute stage-3 threshold to 2.5 mg/dL to reflect the lower neonatal baseline. Standardized staging enables consistent management decisions (nephrotoxin removal, fluid balance, dosing adjustments, dialysis referral) and supports research comparisons across NICUs.
Neonatal AKI Staging (Modified KDIGO)
Enter the reference (lowest previous) SCr and the current SCr to compute the SCr-based stage. Optionally enter the urine output to add the UO-based stage. The final stage is the worst of the two. Dialysis automatically forces stage 3.
"Reference" SCr = lowest previous, not pre-illness baseline
Neonatal SCr falls during the first 1–2 weeks of life as the maternal contribution clears. Use the lowest measured SCr to date as the denominator, not a single early "baseline" value.
⚕ Modified neonatal KDIGO definition (Jetton JG, Askenazi DJ et al.; AWAKEN cohort). Reference SCr = lowest previous SCr, not a pre-illness baseline. Final stage = worst-of SCr and UO criteria; receipt of dialysis forces stage 3. For licensed clinicians; not a substitute for individualized neonatal nephrology assessment.
Next Steps
Use the AKI stage to drive nephrotoxin review, fluid management, and escalation.
- Stage 0 (no AKI): continue surveillance with serial SCr and accurate hourly UO if the neonate has risk factors (asphyxia, sepsis, NEC, nephrotoxin exposure, CAKUT, post-cardiac surgery, ECMO).
- Stage 1: review and minimize nephrotoxins (aminoglycosides, vancomycin, NSAIDs, IV contrast, amphotericin), confirm appropriate renal dosing, optimize perfusion and avoid fluid overload, recheck SCr in 12–24 h, and document the staging.
- Stage 2: as above plus daily weights and strict fluid balance, consider pediatric nephrology consultation, evaluate for CAKUT (renal ultrasound), and address the underlying driver (sepsis source control, NEC management, perfusion optimization).
- Stage 3: urgent pediatric nephrology consultation; review for renal replacement therapy indications (refractory fluid overload, hyperkalemia, severe acidosis, uremia, oligoanuria); continue strict input/output and electrolyte monitoring.
- Pair with the pediatric AKI (KDIGO) calculator for older infants/children and the CKiD U25 eGFR for longitudinal post-AKI follow-up.
Evidence & References
Modified neonatal KDIGO staging criteria
| Stage | Serum creatinine criterion | Urine output criterion |
|---|---|---|
| 0 (no AKI) | SCr < 1.5× reference (lowest previous) | UO > 1 mL/kg/hr |
| 1 | SCr 1.5–1.9× reference within 7 days OR rise ≥ 0.3 mg/dL within 48 h | UO > 0.5 to ≤ 1 mL/kg/hr × ≥ 24 h |
| 2 | SCr 2.0–2.9× reference | UO > 0.3 to ≤ 0.5 mL/kg/hr × ≥ 24 h |
| 3 | SCr ≥ 3× reference OR SCr ≥ 2.5 mg/dL OR receipt of dialysis | UO ≤ 0.3 mL/kg/hr × ≥ 24 h |
Final AKI stage = worst-of SCr and UO criteria. Reference SCr is the lowest previous SCr measured in the neonate — not a pre-illness baseline — because neonatal SCr falls over the first 1–2 weeks of life as the maternal contribution clears and native GFR matures. The absolute stage-3 threshold of 2.5 mg/dL is lower than adult KDIGO and reflects the lower neonatal baseline.
Common drivers of neonatal AKI
| Category | Examples |
|---|---|
| Perinatal / hemodynamic | Perinatal asphyxia / HIE, maternal hypertension or hypotension, shock, congenital heart disease, ECMO |
| Sepsis / inflammation | Early- and late-onset sepsis, necrotizing enterocolitis (NEC) |
| Nephrotoxins | Aminoglycosides (gentamicin), vancomycin, NSAIDs, IV contrast, amphotericin |
| Structural | Congenital anomalies of the kidney and urinary tract (CAKUT) — obstruction, dysplasia |
References
- Jetton JG, Askenazi DJ. Update on acute kidney injury in the neonate. Curr Opin Pediatr. 2012;24(2):191–196.
- Jetton JG, Boohaker LJ, Sethi SK, et al. Incidence and outcomes of neonatal acute kidney injury (AWAKEN): a multicentre, multinational, observational cohort study. Lancet Child Adolesc Health. 2017;1(3):184–194.
- Selewski DT, Charlton JR, Jetton JG, et al. Neonatal acute kidney injury. Pediatrics. 2015;136(2):e463–e473.
