One study found that the chance of having ASD for children born to parents who are in their thirties is up to 10 percent higher than parents who are 25 to 29 years old. The same researchers found that the chance of developing ASD is 50 percent higher when the parents are in their 40s or 50s.
Does The Father Or Mother Carry The Autism Gene? Autism was always thought to have a maternal inheritance component, however, research suggests that the rarer variants associated with the disorder are usually inherited from the father.
Summary. Determining pregnancy-related risk factors for autism is an ongoing area of research. Some risk factors have more evidence of an association than others. Taking certain antiepileptic drugs, being older parents, having a preterm birth, and developing gestational diabetes are believed to be risk factors.
Children with an autistic parent or sibling have 9 times the usual odds of autism and 4.1 times the odds of having autism with intellectual disability.
Children born to older parents are at a higher risk for having autism. Parents who have a child with ASD have a 2 to 18 percent chance of having a second child who is also affected. Studies have shown that among identical twins, if one child has autism, the other will be affected about 36 to 95 percent of the time.
However, a comprehensive analysis found that for a woman over age 35, the chance of having a child with autism is lower than for younger women. That study also suggested that women under age 25 are more likely to have a child with autism than older women.
Advanced parental age at time of conception. Prenatal exposure to air pollution or certain pesticides. Maternal obesity, diabetes, or immune system disorders. Extreme prematurity or very low birth weight.
Background. Many empirical studies suggest that higher maternal age increases the likelihood of having an autistic child. However, little is known about factors that may explain this relationship or if higher maternal age is related to the number of autistic-like traits in offspring.
“Firstborn offspring of two older parents,” Durkin's study noted, “were three times more likely to develop autism than were third- or later-born offspring of mothers aged twenty to thirty-four and fathers aged under forty years.”
There are many different factors that have been identified that may make a child more likely to have ASD, including environmental, biologic, and genetic factors.
Prenatal vitamin deficiency
In addition, a 2022 meta-analysis of 10 studies found that taking folic acid (the synthetic version of folate) in early pregnancy significantly lowers the risk of autism. 9 Taing 400 micrograms (mcg) of folic acid was associated with a reduced risk of autism.
Maternal exposure to hormones during pregnancy is linked to a higher risk of the development of ASD in offspring. Dihydrotestosterone, progestin, and norethindrone exposure can induce significant ERβ promoter methylation and inhibit ERβ expression in offspring.
Since autism is less prevalent in females, autism was always thought to be passed down from the mother. However, research suggests that autism genes are usually inherited from the father.
In the United States, prenatal genetic testing (PGT) for Autism Spectrum Disorders (ASD) is currently available via clinical genetic services. Such testing may inform parents about their unborn child's risk for ASD, prepare parents for the birth of an affected infant, and allow them to arrange for early interventions.
Can autism skip a generation? Yes, it's possible for autism to skip a generation. This is because the genes that contribute to autism can be passed down from grandparents to grandchildren, even if the parents do not have the condition.
Studies that include all siblings born before and after the child who has ASD have found the ASD recurrence risk to be 6-10% (Bolton et al., 1994; Chudley, Guitierrez, Jocelyn, & Chodirker.
One study found that the chance of having ASD for children born to parents who are in their thirties is up to 10 percent higher than parents who are 25 to 29 years old. The same researchers found that the chance of developing ASD is 50 percent higher when the parents are in their 40s or 50s.
Among all families affected by autism, up to 19 percent have more than one child with the disorder, according to one large study. Multiplex families, especially those who have twins, have led to many of the breakthroughs in our understanding of autism.
Due to its lower prevalence in females, autism was always thought to have a maternal inheritance component. However, research also suggests that the rarer variants associated with autism are mostly inherited from the father. Ultimately, autism is a complex condition with 100s of genes involved.
Autism prevalence is reported to be highest among non-Hispanic white children, lower in Hispanic and African American/black children, and highly variable in Asian/Pacific Islanders. More comorbid intellectual disability and delays in expressive language have been observed among Hispanic and African American children.
Research shows that autism can indeed run in families. If you already have one child with ASD, you have a 1 in 5 chance of your next child developing autism. If you have more than one child with ASD, the odds of having another child with ASD are even higher.
Genetics. Genetic factors may be the most significant cause of autism. Early studies of twins had estimated heritability to be over 90%, meaning that genetics explains over 90% of whether a child will develop autism.
Advances in diagnostic capabilities and greater understanding and awareness of autism spectrum disorder seem to be largely driving the increase, the Rutgers researchers said. But there's probably more to the story: Genetic factors, and perhaps some environmental ones, too, might also be contributing to the trend.
Among those with autism, common triggers include disturbing breaks in routine, lack of sleep, jarring “sensory stimuli” (noises, lights, or smells) or even undiagnosed mental health problems. Clearly, it's important to look beyond the behavior itself to identify the underlying cause.