What does it mean to be at-risk for delay or disability?

There are two different types of risk that may produce developmental delay in some children:

Biological or medical risk is a diagnosed medical condition (such as prematurity, low birth weight, Chronic Otitis Media) that may produce developmental delay in some children. 

Environmental risks are those environments that pose a substantial threat to development, including chronic abuse of drugs or alcohol, child abuse, domestic violence, or developmental or psychiatric disability in a caregiver.