TN 2 (02-16)

A. Prematurity

Prematurity is not, in and of itself, a medically determinable impairment. It can be associated with several medical impairments that vary with:

• birth weight,

• gestational age, and

• birth weight for gestational age.

Most infants who are only a few weeks premature and of normal weight for gestational age do not have significant growth delays.

Many premature infants who survive, especially those born with very low birth weight, may have other medically determinable impairments associated with their prematurity.

B. Important terms

1. Premature infant

A premature infant is an infant born at less than 37 weeks of gestation. Another term for premature infants is preterm babies.

2. Chronological Age (CA)

CA is the child’s age according to his or her birth date.

3. Corrected Chronological Age (CCA)

CCA is the CA adjusted by a period of gestational prematurity. CCA = (CA) – (number of weeks premature).

C. When to use CCA

Use CCA for comparison when a child is born prematurely. For growth impairments, use CCA to evaluate an infant born at less than 37 weeks of gestation, until attainment of age 1.

For the definition of premature infant see DI 24598.015B.1.

For guidance on CCA of premature infants, see DI 25215.010.