Babies who are born prematurely often have two ages:
This is up to you.
Remember: When people ask about your baby, they usually are being kind, not nosy.
Most premature babies "catch up" to their peers, developmentally, in two to three years. After that, any differences in size or development are most likely due to individual differences, rather than to premature birth. Some very small babies take longer to catch up. You can stop adjusting your baby's age when it feels most comfortable to you.
Calculating your baby's adjusted age: Example
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Last reviewed August 2009
Chronological age is the age of a baby from the day of birth. Adjusted age is the age of the baby based on his due date. To calculate adjusted age, take your baby's chronological age (for example, 20 weeks) and subtract the number of weeks premature the baby was (6 weeks). This baby's adjusted age (20 - 6) is 14 weeks. Health care providers may use this age when they evaluate the baby's growth and development. Most premature babies catch up to their peers developmentally in 2 to 3 years. After that, differences in size or development are most likely due to individual differences, rather than to premature birth. Some very small babies take longer to catch up.
Late preterm means that a baby is born after 34 weeks but before 37 weeks of pregnancy. It's important to try to have your baby as close to 39 weeks of pregnancy as possible. In the last few weeks of pregnancy, your baby's organs, like his brains, lungs and liver, are still growing. Waiting until you're at least 39 weeks also gives your baby time to gain more weight and makes him less likely to have vision and hearing problems after birth. Your baby will also be better able to suck and swallow and stay awake long enough to eat after he's born. Babies born early sometimes can't do these things.