Know the Age

"How old is this child?" is one of the first questions to be asked about every pediatric patient. When presenting a pediatric case verbally or in a clinic note, always give the name, age and gender (e.g. "Kim is a 30-month old boy ...")

For children under three, age is measured in months, not years; but even for children three to five, it is important to know if they are a "young 3" or an "older 3", for there is considerable amount of development occurring even within the year.

Consider full-term to be 40 weeks. For premature infants (born before 37 weeks gestation), it is necessary to adjust their age when assessing development. Age correction for prematurity should be done for one year for moderate degrees of prematurity, but may be appropriate for up to two years for severe prematurity (i.e. born at less than 30 weeks gestation).

Example: For infant born at 34 weeks, correct with a factor of 6 weeks. Thus, at 6 months after birth (i.e. 24 weeks), the corrected age is 18 weeks, or 4 1/2 months. At 12 months (48 weeks), the corrected age is 42 weeks (or 10 1/2 months).

Correcting for prematurity

If you are assessing development of a 9 month-old born a month early, what is the corrected age to use for assessment?