How do you calculate corrected age for a premature baby?

What does the evidence say about corrected age for premature babies?

1. Calculate weeks early by subtracting gestational age at birth from forty weeks. Then subtract that number from the baby’s chronological age. Use weeks consistently; calendar months have different lengths, so mixing months and weeks can make the estimate confusing. 1
2. Corrected age provides context for early milestones rather than a guarantee about an individual child’s progress. The AAP uses the adjustment through about two years. A child who needs extra support may continue to need follow-up beyond that point. 2
3. Parents’ observations and formal developmental screening complement each other. Share what the baby can do, changes over time and any concerns at well-child visits. A corrected-age calculation does not replace a validated screening tool or an examination. 3
4. Families can contact their state’s early intervention program directly when development is concerning. Eligibility is based on an evaluation and local program rules. Prematurity provides useful history but does not require waiting until a particular corrected age before asking for help. 4
5. If a concern remains after a routine visit, ask what assessment will clarify it and how to arrange that referral. Keep the milestone notes and birth information together so the next clinician can see the pattern over time. 5

Using the calculation at follow-up

• Confirm the birth gestation in the discharge record.
• Compare progress using the age framework recommended by the care team.
• Request evaluation for concerns instead of waiting for the adjustment to end.

Corrected-age examples