What is Corrected or Adjusted Age?
For babies born before the expected due date, there is often an important distinction between chronological age and corrected age. It is important to know the difference between the two terms when discussing your child’s growth and development.
Chronological age refers to the number of days, weeks, months, or years from the date of the infant’s delivery. You calculate the chronological age the same way you would calculate your own birthday. Some facilities also refer to chronological age as actual age.
In contrast, corrected age helps account for your infant’s prematurity. Some facilities also refer to this as adjusted age or post-conceptual age. Corrected age provides a better understanding of how to interact with your infant and a better idea when your infant might meet certain developmental stages and goals.
How Do I Calculate Corrected Age for Preemies?
To calculate corrected age or adjusted age, start with the baby’s chronological age, and then subtract the number of weeks of prematurity from that chronological age.
The simple formula is as follows:
(Chronological Age) – (Weeks of Prematurity) = (Corrected or Adjusted Age)
For example, suppose a 6-month old infant is born at a gestational age of 32 weeks. This means the child was born 8 weeks before the term date of 40 weeks.
Although the chronological age of this infant is 6 months (or 24 weeks), you can calculate the corrected or adjust age as follows:
(6 months) – (2 months) = 4 months corrected or adjusted age
(24 weeks chronological or actual age) – (8 weeks prematurity) = 16 weeks corrected or adjusted age
Why is Corrected or Adjusted Age Important?
Corrected or adjusted age provides a more accurate assessment of a preemie’s development. For example, infants born prematurely at 28 weeks can need another 12 weeks of growth before developmental specialists expect them to function as full-term newborns would. Accordingly, caregiving actions like feeding, handling, and play are all based on a preemie’s corrected or adjusted age. Parents and caregivers should also consider corrected or adjusted age when watching for developmental milestones like gross motor and fine motor skills.
How Long Should I Use Corrected or Adjusted Age?
Most developmental specialists use corrected age for the first 2 to 2 ½ years of life. Since every child is different, health professionals also take into account the number of weeks of prematurity. There is no need to be alarmed, for example, if a 6-month-old born 3 months premature is performing the motor functions of 3 months. This is on target for the child’s corrected age.
(24 weeks) – (12 weeks) = 12 weeks or 3 months corrected or adjusted age.
If you have any questions or concerns about corrected age, contact a development specialist. You can also reach out to the Warren Center for additional information on early childhood intervention for preemies.