Premature infants are smaller and less developed than full term infants of the same postnatal age. If the gestational age at birth is used to correct the postnatal age, then the development of the premature infant can be more meaningfully compared to normal infants.


corrected age in weeks =

= (age in weeks since birth) - (40 - (weeks of gestation at birth))


The age correction should be done for the first year. Afterwards the correction has little if any benefit, and the chronological age can be used.


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