Another day, another survey about Autism that the media is claiming is a cause. This one is about closely spaced pregnancies and the likelihood of baring a child with Autism. It seems that in a survey of 662,730 second-born children in general, parents were three times more likely to have a second-born child with Autism if the pregnancy were spaced less than three years apart. Yet again, genetics were not taken into consideration, just passive observation.
I've posted before about my, erm, thoughts about this type of passive observation. Just like with anything, simple observation of a few facts without seeing the whole picture, such as genetics, cannot do much more than justify making a pitch for additional funding. The article itself, which will be published in the journal Pediatrics in February (click to see web access to article) indicates that the goal of the survey was to compare pregnancy planning, and nothing else. So, based on the data, they had to draw some conclusion, and that was the conclusion they made.
So is it right? Is it the cause? Well, as it is a one in three chance, I don't think so. Just like a previous survey on proximity to freeways during pregnancy term, a pattern was emerging. But let's step back a bit, and see if there is another possible answer.
Could it be that parents with genes associated with Autism may be slow at developing social skills, therefore marrying late and wanting to have children as quickly as possible? I don't know, seems like a reasonable conclusion, but could only be identified by looking at genetic data along with these pregnancy spacing surveys.
Perhaps it's time we start looking at the whole story instead of just trying to look for environmental causes. If I were to council parents now on whether or not to wait to have additional children, I would have them look at all the facts, family history, and then decide if waiting is something they can do, want to do, or perhaps is something they don't want at this time. Right now this survey shows an interesting pattern, but no real, concrete connection to Autism in children. Until then, look at it as at most an interesting pattern.