DI 25215.010 Correcting Chronological Age of Premature Infants
1. Premature Infant
A premature infant is an infant born at less than 37 weeks of gestation. Premature infants are also referred to as preterm babies.
2. Chronological Age (CA)
CA is the child’s age based on birth date. For purposes of disability evaluation, age refers to CA except when evaluating certain premature infants, as defined in DI 25215.010A.l.
3. Gestational Age
Gestational age is the age of the infant based on the date of conception as recorded in the medical record. Gestational age may be:
expressed in terms of the time elapsed from the first day of the last menstrual period of the mother; or,
calculated based on certain physical signs at birth using scoring systems designed for this purpose, such as the Dubowitz forms for assessment.
4. Corrected CA (CCA)
CCA is the chronological age adjusted by a period of gestational maturity.
B. Policy (Section 416.924b(b))
We generally use chronological age (a child's age based on birth date) when we decide whether, or the extent to which, a physical or mental impairment or combination of impairments causes functional limitations. However, if you were born prematurely, we may consider you to be younger than your chronological age when we evaluate your development.
We may use a "corrected" chronological age (CCA); that is, the chronological age adjusted by a period of gestational prematurity. We consider an infant born at less than 37 weeks' gestation to be born prematurely. See DI 25215.010A.1.
2. How We Compute a Corrected CA (CCA)
We compute your CCA by subtracting the number of weeks of prematurity (the difference between 40 weeks of full-term gestation and the number of actual weeks of gestation) from your chronological age. For example, if your chronological age is 20 weeks but you were born at 32 weeks gestation (8 weeks premature), then your CCA is 12 weeks.
We evaluate developmental delay in a premature child until the child's prematurity is no longer a relevant factor, generally no later than about chronological age 2.
We compute a corrected chronological age as follows:
If you have not attained age 1 and were born prematurely, we will assess your development using your CCA.
If you are over age 1 and have a developmental delay, and prematurity is still a relevant factor, we will decide whether to correct your chronological age. We will base our decision on our judgment and all the facts in your case. If we decide to correct your chronological age, we may correct it by subtracting the full number of weeks of prematurity or a lesser number of weeks. If your developmental delay is the result of your medically determinable impairment(s) and is not attributable to your prematurity, we will decide not to correct your chronological age.
3. When We Will Not Compute a Corrected CA (CCA)
Notwithstanding the provisions in DI 25215.010B.2.a., we will not compute a CCA if the medical evidence shows that your treating source or other medical source has already taken your prematurity into consideration in his or her assessment of your development. We will not compute CCA when we find you disabled under listing 100.04 of the Listing of Impairments.
See DI 24598.015 for a discussion on how to evaluate premature infants.