HIGH RISK INFANTS

A developmental delay is diagnosed when a child does not reach a developmental milestone (for example, sitting, walking, or combining words) at the expected age, despite allowing for individual variation in the rate of development. Each year, many children are born at increased risk of a developmental disability or delay. Infant and preschooler development is a complex, dynamic process that begins at birth and evolves as infants interact with their caregivers and environment. Approximately 10 percent of infants will reflect developmental delay.

The key to intervention and rehabilitation lies in identifying those infants at significant risk of developmental disability. However, early identification remains difficult. The normal variation in development among children is broad. Also, development must be monitored in several areas (motor, cognitive, psychosocial) simultaneously, and it can be easy to overlook a small delay in only one area. Parents and pediatricians may be reluctant to discuss their fears that a child may have a developmental delay. Lastly, the age at which developmental difficulties manifest, often depends on the developmental stage of the child. It is common for hyperactivity, language delays, and emotional disorders to be diagnosed at about three to four years of age. However, learning disabilities and mild mental retardation are frequently not diagnosed until a child enters school. Assessment of developmental risk includes medical and social history, physical examination, and developmental observation of the child. Often developmental surveillance tools, such as standardized tests that screen several or all areas of development, are used to help identify the child with delay.

Not all children with developmental disability have known risk factors at birth and many times the cause of delay is not known. An infant with an established risk typically has a diagnosed medical condition known to be associated with a high probability of developmental disability. Examples of conditions with established risk are chromosomal abnormalities (such as Trisomy 21), sensory impairments (such as visual or hearing impairment), and neurological defects.

Risk Factors

There are many influences that can affect development. These influences are termed risk factors and are often divided into biological risk and environmental risk. However, it is recognized that there is often significant overlap and influence between the two categories. Biological and environmental stresses are interactive and together have an additive effect on developmental outcome. Therefore, infants with multiple risk factors typically have a greater risk of disability than infants with single risk factors.

Biological risk factors tend to be associated with more severe developmental disability, mental retardation, and multiple handicaps. Included in this category are prenatal influences such as chromosomal disorders, congenital infections, congenital malformations (both of the brain or other organs), and intrauterine growth retardation. Maternal substance abuse during the pregnancy is also a significant prenatal, and often ongoing, risk factor. Then there are the perinatal (around birth) influences on development. Infants born prematurely are at increased risk of developmental disability. They are also at risk for chronic lung disease, deafness, and brain hemorrhages, which add to their developmental risk. Infants with severe lung disease or neonatal seizures are at increased risk. Some infants have metabolic or endocrine disorders such as hypothyroidism or phenylketonuria, which place them at increased risk without appropriate intervention. Lastly, acquired infections in infancy, particularly involving the brain, can result in compromised development. Children with developmental delay due to biological risk factors are often diagnosed in infancy.

Compromised developmental outcome is due to both biologic and environmental risk factors. Over time, environmental influences affect the development of biologically at-risk children. The environment has the potential to maximize or minimize early developmental delays. Environmental risk factors are cumulative, with each having a small incremental effect on cognitive abilities. The adverse effects of a poor environment become increasingly more evident from about two years of age onward. This influence is most strongly seen in the areas of verbal and general cognitive development. As children age, the tests used to measure intelligence place more and more emphasis on language, and therefore the environmental influences assume greater importance. The reverse is also true: A good environment can have a temporizing effect on the degree of developmental disability, but it does not determine whether the disability occurred. Environmental influence seems to be minimized when the biologic risk is severe.

Environmental risk factors are legion and varied. First, consider that the environment includes caregiver-child interactions, family resources, physical properties, and organization. Within the area of caregiver-child interaction is parenting ability. Limited parenting ability, whether due to youth, inexperience, mental retardation, illicit drug abuse, or mental illness, is a risk factor for developmental disability. Inadequate supervision can lead to accident and injury. Child neglect or abuse increases the risk of developmental compromise. Additionally, parenting ability can be limited due to physical separation because of divorce or incarceration. Caregiver-child interactions also include disciplinary techniques and the family's beliefs and attitudes. All of these can affect development.

Many children at risk of developmental disability often live in families with limited resources, frequently referred to as low socioeconomic status. Housing, financial statuses, maternal education, availability of medical insurance, and availability of appropriate play materials are all part of family resources. Homelessness, poverty, low maternal education, single parent families, and lack of medical insurance have all been associated with increased risk of developmental compromise. Unavailability of medical insurance usually means that preventative medical care, when most developmental surveillance takes place, and prenatal care are not obtained. Additionally, a family's ability to cope when suffering from stressful life events, such as divorce, loss of a job, or death, depends on their own resources and access to external sources of support.

Additional environmental influences impacting development are the physical properties of the environment, such as personal space, crowding, and excessive noise. The level of organization is also an influence. This includes the predictability, structure, and regularity of the home. Over many years, children who live in poor or disorganized families are at increased risk of slower cognitive development and diminished school performance when compared to their peers from more advantaged families.

Intervention and Rehabilitation

The prevention of developmental disabilities starts before conception. Good nutrition and adequate prenatal care are essential components of a healthy pregnancy, assuring the best outcome for an infant, regardless of additional risk factors or disabilities. With improvements in neonatal intensive care and the care of premature infants, there is hope that the risks associated with prematurity will diminish.

Influencing development in children's lives requires a societal commitment to the prevention and rehabilitation of developmental disabilities. In 1997, the Individuals with Disabilities Education Act (IDEA) amendments (PL 105-17) re-established the right to a free and appropriate education for all school-age children, regardless of their disability. Additionally, the federal government provides financial assistance to states for the development of early intervention programs for infants and toddlers with known developmental delays or disabilities and their families. At each state's discretion, infants and toddlers considered at risk for developmental disabilities may be enrolled in early intervention programs.

Early intervention programs are a system of therapeutic and educational programs that work with an infant or young child, from birth to age three, and their family to prevent or minimize adverse developmental outcomes for that child. An infant-toddler specialist typically assists families. Therapeutic approaches could include physical therapy, occupational therapy, or speech and language therapy for the child. These services can be provided through a center-based or home-based model and include encouragement of active parental participation. No single intervention model meets the needs of all children at risk; therefore, an individualized approach to providing services is necessary. Early intervention programs also work in conjunction with other services that assist families in functioning. These other services could include drug counseling programs, home health aides, transportation to medical evaluations, parenting classes, and support groups. At age three, children transition to preschool programs that continue to provide intervention and therapeutic services until age five, when the child transitions into the public school system.

Only a small proportion of at-risk infants go on to have developmental delay. Early intervention services are expensive and time-consuming. Generally, these services are reserved for children with known developmental delay, while a tracking system monitors high-risk infants and identifies developmental delays. Each state determines if at-risk infants will be automatically eligible or monitored for developmental delays and then referred for services.

Early identification of infants at high risk permits parent counseling and planning for the child's future. Early intervention with quality, long-term services can significantly improve the quality of life, minimize secondary complications, and improve cognitive function. But frequently early intervention does not prevent a developmental disability from occurring if the biological risk is high. Additionally, intervention services often help parents through a particularly difficult time.

See also:BIRTH DEFECTS; BIRTHWEIGHT; PREMATURE INFANTS

Bibliography

Allen, Marilee C. "The High-Risk Infant," Pediatric Clinics of North America 40 (1993):479-490.

Aylward, Glen P. "The Relationship between Environmental Risk and Developmental Outcome,"Developmental and Behavioral Pediatrics 13 (1992):222-229.

"Individuals with Disabilities Education Act." In the U. S. Department of Education, Office of Special Education and Rehabilitative Services [web site]. Available from http://www.ed.gov/offices/OSERS/IDEA; INTERNET.

Kruskal, Maureen, Michael C. Thomasgard, and Jack P. Shonkoff."Early Intervention for Vulnerable Infants and Their Families: An Emerging Agenda,"Seminars in Perinatology 13(1989):506-512.

Ostrosky, Michaelene M. "Early Education for Children with Special Needs." In the National Parent Information Network— Parent News [web site]. University of Illinois at Urbana-Champaign, Champaign, Illinois, 1997. Available from http://npin.org/pnews/1997/pnew997/pnew997b.html; INTERNET.

Kristi L.Milowic