Developmental Delay

What is Developmental Delay?

Human development refers to the various physical, mental, and social changes that happen throughout a person’s life. These changes, or ‘developmental lines’, often happen independently and in sequence, while also affecting one another. Some common examples include physical growth, developing motor skills, learning language, cognitive development, personality growth, social and psychological development, sexual development, and the development of everyday skills necessary for living, like cooking or cleaning.

The brain of an unborn baby starts developing in the first three months of pregnancy, specifically in the fourth week, and continues growing rapidly in early childhood. This growth continues, albeit at a slower pace, through teenage years and into a person’s twenties. In fact, the human brain continues to develop to some extent throughout one’s entire life.

When a child does not develop certain skills or traits at the same pace as their peers, they are said to have a ‘developmental delay’. The extent of the delay can range from mild to severe, based on how much slower their development is compared to their age group. ‘Developmental delay’ is a simple term used to describe a wide range of issues, which then need to be investigated further to identify the specific area of slow development. It’s also important to note that the terms used to describe a developmental delay can vary from one country to another or even in different medical practices.

For example, terms like “mental retardation” are no longer used, with modern terms like ‘learning disability’ being used in the UK and ‘intellectual disability’ in the US. These terms refer to significant developmental delays that are identified by specific standard tests (like an IQ test). Delay can occur in a single area (isolated), in two or more areas (multiple), or across most developmental areas (global).

An ‘intellectual disability’ is a type of developmental delay that mainly affects cognitive function. The American Association on Intellectual and Developmental Disabilities defines it as significant lifelong developmental challenges in learning, problem-solving, skill development, and independence, generally starting before age 18.

‘Developmental disorders’ represent a large group of conditions disrupting typical developmental progress, causing both delays and deviations in developmental steps. Despite early screening policies, many developmental disorders remain undiagnosed and untreated.

What Causes Developmental Delay?

Developmental delay, which may cause children to develop skills like walking and talking slower than average, is usually caused by a blend of factors. Many times, we don’t explicitly know what causes it, but it can sometimes be linked to genetic, environmental, or emotional factors.

Genetically speaking, family history often influences developmental patterns. For instance, if a child’s parents were late walkers or talkers, the child may be as well. But these genetic factors can also hint at risk for certain syndromes or disorders. The genetic causes vary widely, and include different changes in the DNA like duplications and deletions. It’s well-known that the Fragile X syndrome, caused by a particular repeating pattern in our DNA, is a common genetic basis for intellectual disability. Besides, Fragile X is also associated with autism. Other genetic conditions like Prader-Willi and Angelman syndromes can also cause developmental delay due to the loss of function in a certain part of chromosome 15. For other cases such as Down syndrome, Edward syndrome, or Patau syndrome, developmental delays are often accompanied by physical abnormalities due to the presence of extra chromosomes or fragments of them.

Environmental factors, or circumstances outside the body, can also influence children’s development. These can interrupt development at any stage, even before birth. Some of these factors include inherited disorders (like Fragile X or Down syndrome), infections in the mother during pregnancy (like rubella or toxoplasmosis), complications during the mother’s first pregnancy, teen pregnancies, and certain prescribed medications. Other harmful substances, like tobacco and alcohol, can also cause issues, along with factors like poverty.

Around the time of birth, conditions like restricted growth in the womb, lack of oxygen to the baby’s brain, or certain metabolic conditions can also lead to delays. Again, financial hardship can play a role here as well.

After birth, factors like metabolic disorders, exposure to harmful substances, head injury, infections, psychological stress, family violence, poverty, and malnutrition can contribute to developmental delays.

Risk Factors and Frequency for Developmental Delay

In 2016, around 52.9 million children worldwide were reported to have identifiable developmental delays. These issues are more prevalent in low and middle-income countries, where 95% of the world’s population lives. The World Health Organization (WHO) says that in every country, approximately 10% of the population has some form of disability. In the United States, about 15% of children reportedly have at least one developmental delay. In England, the prevalence of these delays in children under five and adults is 2.7% and 2.17% respectively.

For school-aged children, the global rate of Generalized Developmental Delay (GDD) is between 1% and 3%. Autism affects about 2.5% of the population.

Different types of developmental delays vary in their prevalence:

• Cognitive delays: between 1% and 1.5%
• Learning disabilities: around 8%
• Speech and language delays: between 2% and 19%
• Any category of delay: about 15%

Studies, including the Drakenstein Child Health Study (DCHS) in South Africa, have found that boys in high-risk environments are more likely to have low developmental performance. This increased risk among boys has been linked to genetic differences on the X-chromosome.

Signs and Symptoms of Developmental Delay

Evaluating children with developmental delays requires a detailed look at the child’s history and a careful physical examination. It’s also useful to watch the child play with age-appropriate toys like toy cars or crayons, observe them in the office setting, and even look at home videos if available.

The child’s entire developmental history from birth to the present day needs to be understood. This includes:

• Getting a detailed family history, possibly including a family tree
• Looking at the development of the child’s delays over time
• Reviewing records from before, during, and after the child’s birth if they are available
• Checking for early life issues such as lack of oxygen at birth, jaundice, weak muscle tone, thyroid problems, or unusual physical features
• Listing key developmental milestones such as sitting, crawling, walking, talking, interacting with others, language development, and learning
• Getting the child’s vaccination history
• Understanding the child’s nutritional history, including their eating habits

Moreover, a thorough medical history should also be taken, comprising information about any hospital stays, surgeries, accidents, or injuries, the child’s medications, and their performance at school.

The physical examination should measure their head size, weight, and height to calculate their body mass index (BMI). A general physical examination should be conducted from head to toe, including a thorough neurological exam with hearing and vision assessments. The physical exam should also be targeted to look for abnormal physical features.

Testing for Developmental Delay

Assessing developmental delays in children often involves a team of professionals including primary care providers, pediatric specialists like neurologists and child psychiatrists; and other experts from fields like psychology, speech and language pathology, or occupational therapy. It’s vital that these professionals have a thorough understanding of developmental milestones, along with awareness of the various screening tests and their effectiveness, to ensure accurate screening and referrals.

During routine check-ups, doctors should encourage parents to voice any concerns about their child’s developmental progress or behavior. As developmental delays can either be due to normal variation, or indicative of a developmental disorder such as autism or cerebral palsy, it’s essential that evaluations and follow-up are carried out diligently.

Regular use of approved screening tools during each check-up aids in the early detection of any developmental problems. Parental concerns as well as observations from medical professionals should trigger this kind of screening. Standard routine sees screenings at 9, 18, and 30 months of age, with a specific autism test recommended at 18 and 24 months. Tools such as the Ages and Stages Questionnaire (ASQ-3) and the Parents’ Evaluation of Developmental Status (PEDS) are commonly used to achieve this.

When it comes to laboratory tests for children with developmental delays, these should be carried out cautiously, taxking into account both appropriate use of resources and benefit-risk analysis. Standard tests include complete blood count (CBC), electrolytes, and lead screenings. Additional tests may involve checking levels of iron, calcium, creatinine kinase enzyme, and others, depending on individual cases.

Generally speaking, genetic testing isn’t carried out for developmental delay unless there are specific indications or signs of a particular syndrome. In the same vein, brain MRIs are mostly reserved for cases involving discrete family history, specific injury, or notable neurological findings. Similarly, EEG (brain wave) studies are rarely used in routine assessments of children with developmental delays unless there is observable seizure activity or history of regression.

In conclusion, children with developmental delays are usually identified due to concerns expressed by parents or teachers, or observations made during routine care in primary care settings. When such observations or information is provided, the primary care provider should take it seriously and conduct an attentive evaluation of the developmental delay and its potential causes.

Treatment Options for Developmental Delay

Treating a developmental delay involves a team of medical professionals including doctors, specialists like neurologists, psychiatrists, and pediatricians, as well as therapists and counsellors. The approach typically involves various treatment strategies and revolves around the child’s unique needs.

The primary health care provider often takes the lead in developing a relationship with the team to guide the child’s care. This involves letting parents or caretakers understand the nature of the developmental delay, potential syndrome signs, the course of the disorder, its diagnosis, prognosis, and potential complications. Parental counselling and emotional support are substantial elements of care plans. The information should be given in an understandable way to encourage the families to follow the treatment plans closely.

Support from social workers might be essential for some families. Their services could include coordination, arranging transportation, regular home visits, and other necessary services to complete developmental evaluations.

Alongside routine medical appointments, early interventions strategies that could help the child include early childhood education, specific intervention programs, and timely screenings and treatments. In cases where parents are struggling, parent-child interaction therapy, which involves parent-directed and child-directed interactions, could be suggested. Parents may also need support in creating stimulating environments for their children at home, school, and daycare settings.

Children with developmental delay are usually eligible for community-based services. These could include referring a child to a child and adolescent psychiatrist or a behavior therapist in case of behavior problems. In case of social skills problems, social skill training could be considered. Other referrals can cover areas like hearing, vision, motor skills and speech & language delay. They can be referred to audiologists, ophthalmologists, physical or occupational therapists and speech specialists as necessary.

Programs like HeadStart and special education are also available through Individualized Education Programs or 504 Plans. Being familiar with these services and knowing how to make appropriate referrals is crucial for primary health care providers in managing cases with developmental delay.

What else can Developmental Delay be?

Developmental delay in children often occurs without any known cause and usually only lasts for a short period. However, for some children, this delay may hint at a deeper issue known as a “developmental disorder”. Specialists can diagnose these disorders through specific procedures. There are many types of developmental disorders, including:

• Intellectual disability
• General developmental delay
• Fragile X syndrome
• Failure to thrive
• Anemia, which is a lack of healthy red blood cells
• Thyroid deficiency
• Social deprivation, which is a lack of access to social resources

Delayed speech and language can be the result of factors like:

• General speech delay
• Developmental language disorder
• Autism spectrum disorder, a condition related to brain development that affects communication and behavior
• Social communication disorder, a persistent difficulty using verbal and nonverbal communication

Sensory impairments can affect a child’s ability to hear or see properly:

• Developmental hearing disorder
• Developmental vision disorder

Behavioral problems can manifest in several ways, including:

• Attention deficit hyperactivity disorder
• Oppositional defiant disorder, a pattern of angry/irritable mood, argumentative/defiant behavior, or vindictiveness
• Disruptive mood dysregulation disorder, characterized by severe temper outbursts
• Childhood-onset schizophrenia, a rare mental disorder where children interpret reality abnormally

Mood or emotion regulation issues can arise from:

• Autism spectrum disorder
• Intellectual disability
• Mood disorders, such as depression or bipolar disorder

Learning problems can be due to:

• Intellectual disability
• Sensory deficits
• Dyslexia, a learning disorder involving difficulty reading

Motor delays and movement disorders can be due to:

• Cerebral palsy, a group of disorders affecting a person’s ability to move and maintain balance and posture
• Muscular dystrophy, a group of diseases that cause progressive weakness and loss of muscle mass
• Tourette syndrome, a disorder that involves repetitive movements or unwanted sounds

What to expect with Developmental Delay

Mostly, developmental delays improve on their own, so generally, the outlook is good. However, they also significantly increase the risk of developing into a neurological disorder or syndrome. Due to this, it’s very important to keep a close eye on any developmental delay until it’s either resolved or develops into a disorder. There are many factors that can either improve or worsen the developmental outcome.

Some factors can lead to poor behavioral outcomes or serious delays in kids between 18 and 30 months. These factors include a lack of parental education, anemia during pregnancy, malnutrition, being born prematurely, being male, low birth weight, depression before or after birth, violence towards a partner, the use of drugs, tobacco, or alcohol during pregnancy, and poverty.

There are also some signs to watch out for. These include loss of hearing or vision at any age, losing previously learned skills, consistently low or high muscle tone, uneven movements, not speaking at 16 months old, and a head circumference that’s either less than 0.4 percentile or greater than 99.6 percentile. These could result in a significant developmental deficit if not timely addressed.

On the other hand, factors such as maternal education, access to basic necessities and healthcare, and being an older child have been associated with better outcomes.

Possible Complications When Diagnosed with Developmental Delay

Most of the time, developmental delays get better on their own without any problems. However, if these delays turn into developmental syndromes, they need to be carefully evaluated by professionals who are experts in the areas impacted by the developmental issues.

Preventing Developmental Delay

Children usually outgrow developmental delays, however, creating environments that stimulate various areas of their development such as thinking, physical movement, sensory, emotional, social, and psychological can help prevent or shorten the length of these delays. Such environments can be in homes, schools, daycare centers, etc. Educating parents about the needs of their children and the potential risks associated with developmental delays can be beneficial. As such, guidance for parents should be incorporated into every prenatal and routine child health check-up.

Several training programs have been designed to help parents and other caregivers understand and manage developmental delays. One example is the Caregiver Skills Training program (CST), created by the World Health Organization (WHO) for families of children with developmental disorders. This program consists of:

* Engagement (2 sessions)
* Communication (2 sessions)
* Behaviour management (2 sessions)
* Play and home routine (1 session)
* Adaptive behaviour (1 session)
* Caregiver self-care and ongoing practice (1 session)

In addition to this, it’s important for communities to provide supportive services for parents and children, including:

* Safe environments
* Proper sanitation facilities
* Clean drinking water
* Proper nutrition
* Prenatal care
* Postnatal care for women, including maternity leave
* Regular health checks for children
* Early childhood education
* Preschool for all
* Quality education
* Universal developmental guidance and support

Most parents are capable and care a great deal about their children. Healthcare professionals should encourage and support parents in their child-raising journey. This includes encouraging parents to voice their concerns and taking all parental comments and concerns seriously. It’s crucial for doctors and healthcare providers to listen and provide necessary support to parents.