Fenton 2013 Preterm Growth Calculator
Calculate Fenton 2013 preterm growth z-scores and percentiles for weight, length, and head circumference using postmenstrual age (22w4d–50w). Harmonized with WHO growth standards for NICU growth monitoring.
Pair with the gestational age calculator, AAP phototherapy chart, and neonatal BP percentiles.
How to interpret Fenton 2013 preterm growth
Plot measurements by postmenstrual age (PMA): gestational age at birth plus day of life. A z-score of 0 is the 50th percentile for that PMA and sex. Values near −2 or +2 (about the 2nd and 98th percentiles) warrant closer review in context of nutrition, illness, and serial trend—not a single-point diagnosis.
Results include expected weekly gain to maintain the current z-score, useful for NICU nutrition planning. Compare serial points over time; crossing major percentile bands or falling weight velocity may prompt feeding or workup changes per unit protocol.
Fenton 2013 vs Fenton 2025
Fenton 2013 remains widely used in NICUs and is harmonized with WHO post-term standards. Fenton 2025 uses a third-generation meta-analysis excluding abnormal fetal growth. Many units still document on 2013; we provide both so you can match local policy. See the Fenton 2025 calculator for the newer reference.
Sources and Reference Basis
Fenton 2013 LMS parameters are derived from published preterm growth meta-analysis data harmonized with WHO Child Growth Standards. Use for bedside screening and documentation; interpret with clinical context and serial measurements.
- Fenton TR, Kim JH. A systematic review and meta-analysis to revise the Fenton preterm infant growth chart. Pediatrics. 2013 Primary reference for Fenton 2013 preterm growth charts.
- WHO Child Growth Standards Harmonization basis for post-term portion of Fenton curves.
- PediaHelper gestational age calculator Compute PMA from birth GA and assessment date.
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Frequently Asked Questions
What is the Fenton 2013 growth chart?
The Fenton 2013 chart is a revised preterm growth reference harmonized with WHO standards, used to monitor weight, length, and head circumference from 22 to 50 weeks postmenstrual age.
What postmenstrual age should I enter?
Use exact PMA in weeks (e.g. 28.6 for 28 weeks 4 days). Use the gestational age calculator if you need PMA from birth GA and day of life.
How is this different from Fenton 2025?
Fenton 2025 uses a newer third-generation meta-analysis excluding abnormal fetal growth. Many NICUs still use Fenton 2013; we provide both.