If you're one of those people who love to over-analyze everything including the time your baby was born, then you might have wondered if there is a peak month for autistic babies. Well, wonder no more my fellow neurotic parent because today we'll delve into this topic with extreme scrutiny.
Before we jump into the statistics and start using words like "regression analysis" let's make sure we understand autism first. Autism is a spectrum disorder that affects communication, behavior and social interaction skills. It can be diagnosed as early as 18 months old but it usually becomes noticeable around 2-3 years old.
Despite serious advancements in research, scientists still don't know what causes autism although genetics seem to play an important role in its development. Autism affects all races and genders equally around the world - it's pretty democratic when it comes to being annoyingly ubiquitous.
But let's get back on track here - the peak month for autistic babies! Some studies suggest that certain months have higher rates than others whereas other studies argue otherwise. Confusing? You betcha.
Study #1: Valproate Exposure
A study published by Burstyn et al. showed that pregnant women exposed to valproate sodium (used in medication for epilepsy or bipolar disorder) had considerably increased risk of having children with autism spectrum disorders (ASDs).
The same study found an increased incidence of birth-month clustering among ASD cases compared with controls not exposed to teratogens(chemical substances known causing developmental abnormalities). Specifically, November had significantly fewer-than-expected births while March had significantly more-than-expected births among cases.
While this might sound compelling at first read (let's face it - they used scientific jargon) further statistical analysis must be done before definitive conclusions are drawn from these findings.
It's worth noting that ASD is rare, with only about 1 in every 59 children affected.
Study #2: Schizophrenia
Another Burstyn study, this one linking the birth months of parents to mental health disorders of their offspring (yup - that means your bad juju could affect your future baby regardless if you're already dead or not), found a significantly increased risk for people born between January and March when it came to schizophrenia.
However, these findings still do not provide concrete evidence for autism having a peak month due to lack of correlation between birth dates and prevalence rates.
The Other Side
Despite plenty of peer-reviewed literature on this subject matter we can't draw any definitive conclusions from said previous studies because researchers have come up with conflicting results using different methods. So let's look at the other side of argument (all arguments deserve some semblance of equity right?)
A team led by Levy et al., studied records from 5 US states over an extended period starting in 1992 where they found no significant differences when it comes to ASD diagnoses during specific months as well as days. This study was based on very large samples and included all ethnicities but guess what? The same limitations are applicable here too! Correlation does not equal causation!
Let's put both sides into perspective before jumping into conclusions why don't we?
While there were certainly flaws in Burstyn's research such as its small sample size and limited scope, its claim regarding prenatal exposure deserves attention nonetheless (I'm giving the benefit of the doubt here) since valproate has been shown to increase risks. But then again Levy's extensive testing only prolong our pursuit towards finding out if there really is a relation between certain timeframes/dates with autistic babies.
Unfortunately folks, whether or not autistic babies do cluster around certain times/months remains uncertain just like how I am unsure why my toddler finds it appropriate to frequently drool on himself.
Until further research is done with compelling evidence otherwise, we should stick to our trusty pregnancy guides and keep taking folic acid even when we're not pregnant (just in case).