Growth and Development, Ages 12 to 24 Months - What to Expect
Babies who were born early (premature)
Until age 2, a child born prematurely (3 or more weeks early) will have growth
and development milestones adjusted based on
gestational age. To figure out your baby's adjusted
(corrected) age, doctors subtract the number of weeks your baby was born early
from his or her current age. For example, the corrected age of a 17-month-old
baby who was born premature at 30 weeks is between 14 and 15 months.