Risk factors that can cause developmental delays

90–100%

90–100%

chance of developmental delays when children experience

6 or 7 risk factors

Significant adversity impairs development in the first three years

of life—and the more adversity a child faces, the greater the odds

of a developmental delay. In fact, risk factors such as poverty,

caregiver mental illness, child maltreatment, single parenthood,

and low maternal education have a cumulative impact: children

exposed to six or seven of these risks face a 90–100 percent

likelihood of having one or more delays in their cognitive, language,

or emotional development.

Source: Barth, et al. (2007). Developmental Status and Early Intervention Service Needs

of Maltreated Children. Washington, DC: U.S. Department of Health and Human Services,

Office of the Assistant Secretary for Planning and Evaluation

I would like to add that I have seen children with both parents and they  are delayed because if the parents do not have the knowledge or skills themselves most likely they will not be able to give it to their infants/toddlers.