Key takeaways: Adjusted age (also called corrected age) is your baby’s age minus the number of weeks they were born early. Use it to track milestones, often until about age 2. Vaccines are given by actual (chronological) age. Many preterm babies catch up, and follow-up programs and early intervention can help.
If your baby was born early, comparing them to babies born on time isn’t fair. Adjusted age helps.
How to Calculate It
- Find how many weeks early your baby was born (40 weeks minus gestational age at birth).
- Subtract that from your baby’s age since birth.
Example: a baby born at 32 weeks (8 weeks early) who is 6 months old has an adjusted age of about 4 months.
When to Use It
- Milestones: compare to babies of the adjusted age.
- Growth: doctors often plot growth by adjusted age.
- Starting solids: many doctors use adjusted age and readiness signs.
When Not to Use It
- Vaccines: given by chronological (actual) age, unless your doctor says otherwise.
How Long to Adjust
Many experts adjust until about 2 years of age, when most preterm babies have caught up. Very preterm babies may be adjusted longer.
Follow-Up for Preterm Babies
- NICU follow-up clinics for babies born very early or with medical needs.
- Developmental screening at regular visits.
- Early intervention: babies born very preterm or with low birth weight may qualify automatically in some states.
- Eye and hearing checks as recommended.
Emotional Support
It’s natural to worry about milestones. Focus on your baby’s progress over time, and reach out to NICU parent support groups.
Talk to your baby’s doctor if: your baby isn’t making progress by adjusted age, loses skills, or seems very stiff or floppy.
The Bottom Line
Use adjusted age to track your preemie’s development, usually until age 2. Vaccines go by actual age. Follow-up programs can help.
Want more support for your baby’s first year? My book, From First Breath to First Birthday, is available on Amazon.
Sources
- American Academy of Pediatrics. Corrected age for preemies. HealthyChildren.org. https://www.healthychildren.org
- Engle WA; Committee on Fetus and Newborn. Age terminology during the perinatal period. Pediatrics. 2004;114(5):1362-1364.
- Centers for Disease Control and Prevention. Milestone checklists; early intervention. https://www.cdc.gov/ncbddd/actearly
This article is for general education and is not a substitute for individualized medical advice. Always talk with your baby’s health care provider or your own provider about your specific situation. If you think your baby or you may have a medical emergency, call 911.
