Attachment A: Calculating Gestation-Adjusted Age

Instructions

• Document the infant’s gestational age in weeks. (Mother/caregiver can self-report, or referral information from medical provider may be used.)

• Subtract the child’s gestational age in weeks from 40 weeks (gestational age of term infant) to determine the adjustment for prematurity in weeks.

• Subtract the adjustment for prematurity in weeks from the child’s chronological postnatal age in weeks to determine the child’s gestation-adjusted age.

∗ For WIC nutrition risk determination, adjustment for gestational age should be calculated for all premature infants for the first 2 years of life.

Example

Randy was born prematurely on March 19, 2001. His gestational age at birth was determined to be 30 weeks based on ultrasonographic examination. At the time of the June 11, 2001 clinic visit, his chronological postnatal age is 12 weeks. What is his gestation-adjusted age?

• 30 = gestational age in weeks
• 40 – 30 = 10 weeks adjustment for prematurity
• 12 – 10 = 2 weeks gestation-adjusted age

His measurements would be plotted on a growth chart as a 2-week-old infant.