What is corrected age and when should I use it?

Two ages can make everything look confusing

Ari was born in July at 33 weeks and was due in September. For development, those missing weeks matter.

Without corrected age, a premature baby can look behind on every chart while actually progressing exactly as expected. Understanding that removed a huge amount of worry for us.

Count from the due date

Corrected age is the age your baby would be if they had been born around their due date. A baby born seven weeks early may reach a milestone roughly seven weeks later than a term baby and still be on track.

We used corrected age for things such as milestones, early feeding expectations and sleep. It helped us compare Ari with the right stage rather than with babies who had seven extra weeks to practise.

It does not apply to everything

Vaccinations are usually based on actual age, not corrected age. Other medical appointments may use one or the other depending on what is being assessed.

We learned to ask which age was being used instead of assuming. Corrected age usually becomes less important over the first two years, until one day you realise you have stopped doing the maths.