Preterm Growth (Fenton)
Computes weight, length and head-circumference z-score and percentile by postmenstrual (corrected) age using the Fenton preterm reference (22–50 weeks). Informational only; not a diagnosis.
This tool is informational; it does not diagnose. Use postmenstrual (corrected) age. The open Fenton table used here is sex-combined; the sex-specific 2013 version is license-gated. Preterm growth should be followed by a clinician.
Frequently asked questions
What is the Fenton reference?
The Fenton preterm growth chart assesses preterm infants’ growth by postmenstrual age. This tool computes z-score and percentile for weight, length and head circumference (22–50 weeks).
What is postmenstrual (corrected) age?
A preterm infant’s age is assessed by corrected age: gestational age at birth plus time since birth. A baby born at 28 weeks who is 4 weeks old is at 32 postmenstrual weeks.
Is this table sex-specific?
No. The open Fenton reference used here is sex-combined. The sex-specific 2013 version is license-gated and not used; keep this in mind when interpreting.
Is a low percentile a concern?
The trend matters more than a single point. Most preterm infants show catch-up growth in the early years. A marked, persistent drop or absent catch-up should be reviewed by a clinician.