What are the Chances that Your Second Child May Also be Autistic?
Many parents who already have an autistic child wonder if their next pregnancy will bring forth another for them to love, cherish, and become utterly frustrated over, given that the prevalence of siblings with mental disabilities is high. With all the problems a typical child brings to the world with it, one diagnosed with autism almost seems to count as having 3 or more at a time.
Autism is a genetic disorder. Now, there may be theories or individuals who counter this fact, but the truth is that between twin studies and research on genetic markers, there cannot be another way of looking at it. Environmental factors obviously do come into play. After all, cities full of pollution increase the risk of having an autistic child as much as, if not more than, gaining excessive amounts of weight during pregnancy. Some of the strangest or sometimes rather likeliest things connected to autism include:
- A 2008 link to rainfall
- A 2011 linked to closely spaced pregnancies
- A 2010 link between a mother's age and autism was accentuated by a 2013 link to increased paternal age
- A 2012 link to the typical American diet including High Fructose Corn Syrup
Currently there is a strong debate about vaccines being a risk factor. I personally am unsure on where to stand on the issue as there are studies both for and against the argument and angry parents yelling at one another left, right, and center when the topic is introduced into a forum. I, like many others, will wait until there is sufficient evidence in either side's favor before deciding where I stand on the issue.
Prevalence Increase Over Time
There is another truth to consider as well. There has been a steady increase in the prevalence of autism across the board. Let's consider some numbers:
- A 2009 study found that prevalence of autism was highest among Somali children, though reasons were unclear as to why.
- In 2009, the Center for Disease Control and Prevention stated that autism was underestimated by 5-22%.
- In 2010, an article was published on EmaxHealth where the official statistics pointed towards 1 in every 110 children being diagnosed on the spectrum, out of which 1 in 70 were boys.
- This prevalence was seen as an under-diagnosis in itself in a study looking at the US, Canada and South Korea.
- At the moment, one in 88 children are diagnosed on the spectrum, a rate that is believed to not yet be representative of the true population. Between the 2002 and the 2008 data pertaining to the prevalence of the disorder, a whooping 78% increase can be seen.
Will My Second Child Also be on the Spectrum?
According to hefty research presented by the CDC, you have between a 2 and 18% chance of giving birth to a second child with autism. Among twins, there is up to a 95% chance that both will be on the spectrum if identical, and up to 31% chance if they are fraternal.
Childhood autism accounts for about 30% of all autism cases currently recorded, according to a Danish study. The study discovered that a sibling is over seven times more likely to be on the spectrum when combing through the data of 1.5 million people born between 1980 and 2004. The official data says that where full siblings are about 7.5 times more likely to have autism recur in the family, half siblings showed a rate of only 2.4 when the mothers were the same. On the other hand, no significant risk was found when the fathers were the same but mothers different. This leads one to believe that the mother holds most of the cards when it comes to the prevalence of childhood autism.