why do we refer to infants above a year in months?

Question

For example we refer to infants over a year as 13 months, 16 months, 24 months, etc. Is there a reason for this convention?

In: Biology

Answer 1

We use months to refer to their age because that is how we measure their developmental milestones. Babies develop really quickly, although most of the developments are quite subtle.
For example, a baby at 9 months old should be able to stand WITH assistance. They can put themself in a sitting position, or sit without support. A baby at 18 months should be able to walk independently, or even jump.
If a baby cannot meet their expected milestones by the time they reach a certain month, we must try to figure out what is causing this delay.