Actual vs Adjusted/Corrected Ages

For babies born at or after 37 weeks, the day they were born is the date used to determine if they are meeting the CDC Developmental Milestones. For babies born 36 weeks of earlier this is not the case, instead doctors will use their Due Date to determine if they are meeting their developmental milestones. This is done until the age of 2.

Let's break it down further so that we can understand why doctors do this.

• The age of your baby based on the day your baby is born (their birthday) is known as their actual age.

• The age of your baby based on the day they were supposed to be due (your due date) is known as their adjusted/Corrected age.

  • To find your baby's adjusted age, essentially you would take your due date and subtract their birthday.

    
    

• Doctors use the adjusted age to give babies born early grace and time to catch up developmentally to their full-term peers. For a preemie baby, it is expected that they will be developmentally caught up by the Actual Age of two.

• This is specifically used to determine how your child should be acting developmentally for the first two years of their life. This does NOT change your child's birthday.

So how do you find your baby's adjusted/corrected age?

Your Due Date (40 weeks) - Your Baby's Birthday (the gestational age your baby was born at) = Adjusted/Corrected Age

Example:

My baby was due October 2nd (40 weeks) - She was born June 14th (24 weeks +2 days gestation)=

Her Adjusted/Corrected Age at:

Birth: -16 weeks & 2 days

1 Month: - 12 weeks & 2 days

2 Months: - 8 weeks & 2 days

3 Months: - 4 weeks & 2 days

3 Months & 28 Days: 0 days old

4 Months: 2 days old

5 Months: 1 month old

6 Months: 2 months old

(at this point, I can reasonably expect my child to begin meeting the CDC 2-month-old Milestones such as: looking at my face, smiling, responding to loud noises, holding their head up when on their tummy, moving both arms and legs, opening their hand, etc.)

At a year old it would be reasonable for me to expect my child to meet the milestones of an 8-month-old, and so on.

One of my favorite Apps to use to help keep my expectations in check and to see if my daughter is missing any milestones based on her adjusted/corrected age is the Milestones App by the CDC. It allows you to put in both your child's due date and birthdate and gives the correct milestone list that best suits your baby's adjusted/corrected age.

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