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Raising your premature baby

A guide for moms with preemies

Corrected and chronological age

Knowing your premature baby's two ages will help you and your doctor track your preemie's development.

Full-term infants are born with the benefit of having spent 40 weeks of time in the womb, time that allows for organs and vital systems to develop to the point considered mature.

As a result, your preemie might experience developmental milestones differently than full-term babies, accomplishing such things as crawling and balancing; communicating and understanding; using his hands to eat, play, and draw; and thinking and interacting closer to his corrected age than his chronological age. In order to evaluate premature babies’ development, and his development compared to other children his age, his doctor might track his corrected age for one year or longer.

Chronological age is your baby's age from his actual date of birth. Corrected age (also known as adjusted age) is your baby's age based on his due date. To calculate it, subtract the number of weeks he was born early from his chronological age.

For example, a 10-week-old who was born 8 weeks early has a corrected age of 2 weeks old.

Calculate your preemie's corrected age

Select Actual Birth Date

Number of Weeks Premature

Please select your child's birth date.
Please select the number of weeks premature.

Currently, your baby's age is:

Chronological Age
Corrected Age
Keep learning about your baby's development every week
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