Many psychiatrists use the criteria spelt out in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5)&f=false). It is a guide created by the American Psychiatric Association used to diagnose mental disorders. According to this guide, people with ASD have:
- Difficulty with communication and interaction with other people
- Restricted interests and repetitive behaviours
- Symptoms that hurt the person’s ability to function properly in school, work, and other areas of life
Autism is known as a “spectrum” disorder because there is wide variation in the type and severity of symptoms people experience. ASD occurs in all ethnic, racial, and economic groups. Although ASD can be a lifelong disorder, treatments and services can improve a person’s symptoms and ability to function. The American Academy of Pediatrics recommends that all children be screened for autism. All caregivers should talk to their doctor about ASD screening or evaluation.
The number of children diagnosed with autism spectrum disorder is rising [1]. At this point of time, it is not clear whether this is due to better detection and reporting or a real increase in the number of cases, or both.
While scientists do not know the exact causes of ASD, research suggests that genes can act together with influences from the environment to affect development in ways that lead to ASD [2]. ASD affects children of all races and nationalities. However, there are certain factors increase a child's risk.
With that said, we have learned that there are likely many causes for multiple types of ASD. There may be many different factors that make a child more likely to have an ASD, including environmental, biologic and genetic factors.
These may include: [2]
The child's sex
Boys are about four times more likely to develop ASD than girls are.
Family history
Families who have one child with autism spectrum disorder have an increased risk of having another child with the disorder. It's also not uncommon for parents or relatives of a child with an autism spectrum disorder to have minor problems with social or communication skills themselves or to engage in certain behaviours typical of the disorders.
Other disorders
Children with certain medical conditions have a higher than normal risk of autism spectrum disorder or autism-like symptoms.
Examples include fragile X syndrome, an inherited disorder that causes intellectual problems; tuberous sclerosis, a condition in which benign tumours develop in the brain; and Rett syndrome, a genetic condition occurring almost exclusively in girls, which causes slowing of head growth, intellectual disability and loss of purposeful hand use. Persons with Down syndrome are more likely than others to have ASD
Extremely preterm babies
Babies born before 26 weeks of gestation may have a greater risk of autism spectrum disorder.
Parents' ages
There may be a connection between children born to older parents and autism spectrum disorder, but more research is necessary to establish this link.
Drug prescriptions
When taken during pregnancy, the prescription drugs valproic acid and thalidomide have been linked with a higher risk of ASD.
There is some evidence that the critical period for developing ASD occurs before, during, and immediately after birth.
With regards to prevention, there is no way to prevent ASD, but there are treatment options. Early diagnosis and intervention is most helpful and can improve behaviour, skills and language development. Intervention is helpful at any age. Though children usually do not outgrow ASD symptoms, many of them do learn to function well.
You ask about increasing the odds of having a normal child. It will be good to have children when you are relatively young and try to avoid some of the risk factors mentioned above, e.g. exposure to valproic acid during pregnancy.
References:
1. CDC. Research on Autism Spectrum Disorder. Centers for Disease Control and Prevention. Published September 24, 2019. Accessed November 20, 2019.
2. Chaste P, Leboyer M. Autism risk factors: genes, environment, and gene-environment interactions. Dialogues in clinical neuroscience. 2012;14(3):281-292. Accessed November 20, 2019.
