[johnnyg]

Prematurity is linked to developmental delay and is suspected to be correlated with more pronounced Autism spectrum attributes.

I wonder, in addition to the likely chemical sources, how many more children born early are saved than were in previous decades, and how they may be contributing to this rise.

I know that Surfactant has been around for decades now and I suspect but don't have data that it was the last truly game changing upgrade to NICUs.

The CDC has said with this data "this is up". I think the data is out there to also give a range of reasons and a likelihood for each.

On a personal note, if you suspect your child may be at risk for Autism, early therapy is available and effective. Get it, get it now, get as much of it for your child as you can. My contact info is in my profile and I am happy to point you to the data and assistance.

[paulddraper]

Multiple studies link parental age to autism. Teenage mothers, and to a much greater extent older parents (especially fathers) have a higher chance of autistic children.

http://www.npr.org/sections/health-shots/2015/06/10/41320592...

https://www.autismspeaks.org/science/science-news/study-ties...

https://www.autismspeaks.org/science/science-news/large-stud...

It doesn't seem to be enough to account for the whole difference, but given the increasing parental age at birth, it's an appealing theory. Lots of developmental disorders, e.g. Down's syndrom, have already been linked to older parents.

I know "45 is the new 25" is popular, but biology is harder to convince.

[Zenst]

Aspie here, my parents mid 20's when I was conceived and I was a week late being born.

Would in retrospect say my farther was also somewhat upon the spectrum, so genetics are a factor. If those genetics can be activated or induced by other factors, I can not say though like all DNA we have which is dormant in some and not in others, external factors can come into play by that stress, chemical (environmental or self induced exposure) and other factors we are still learning about. Heck recently identified an organ in the humanbody that we had overlooked for all this time ( http://www.independent.co.uk/news/science/new-organ-mesenter... )

So who knows. All we do know is once a trait becomes the predominant trait in humanity then that is classed the new normal.

[notahacker]

Since the recorded increase is large and for births within the last 25 years I suspect that changes in diagnosis play a bigger role in the increase than more gradually-changing birth ages and pre-term survival rates (much as I'd like to believe the latter was of huge importance and not just a potentially relevant factor since the relationship between preterm birth and inattention was the subject of my sister's PHd research...)

[sjg007]

Except most kids with Down syndrome are born to young mothers... the risk is higher with older mothers but young women still make up the majority of new mothers.

[DenisM]

Perhaps autistic fathers are taking more time to find a mate, and they also pass on their genes.

[nkrumm]

The underlying biology of spermatogenesis is also involved. As males age, the germ cells (~stem cells) that produce sperm are continuously dividing. One of the daughter cells from the division becomes sperm, the other continues on as a germ cell [0]. Over time and with aging, the germ cells accumulate new mutations (primarily single nucleotide changes), which are then also passed on in the newly created sperm. While it is also possible that a mother's eggs carries a new mutation, these do not increase in frequency with aging because her eggs are created in utero and do not undergo the lifetime of regeneration that the father's sperm do.

These "de novo" mutations can sometimes affect or "break" genes important for normal development, thus resulting in autism. They can be studied by sequencing father/mother/child families and comparing the genetic sequence of each. The de novo mutations show up in the child only. We can differentiate if they arose in the father's sperm or the mother's eggs by examining the "haplotype" around each of these mutations (basically, looking for other nearby mutations that were inherited by the child from either mom or dad).

For more on this, see this paper: https://www.ncbi.nlm.nih.gov/pubmed/22495309

[0]: https://en.wikipedia.org/wiki/Spermatogenesis#/media/File:Sp...

[paulddraper]

Plausible.

Maybe autistic potential fathers find more acceptance in today's nerd culture, and have the opportunity to pass on autistic genes :)

Early studies showed autism as 90% generic, but more recent ones put it much lower.

[loeg]

That wouldn't explain why the rate is increasing, unless these autistic fathers are having higher than average children despite starting at a higher age.

[gech]

I thought the rise of market economics would bring about better humans because its more efficient and just generally the best system for humans?

[anotherevan]

One anecdote here: Both my daughter and son are on the spectrum (high-level autistic, or aspberger). Daughter was born when I was 29 and wife was 34, son three years later (so perhaps a little older than average). Neither was especially premature (both about 5-6 days early from memory) and very smooth pregnancies.

Son was diagnosed at age seven, daughter at age fifteen. Generally it can be harder to pick up with girls. They tend to be better mimics and it can present much more subtly. I really wish we had figured it out sooner with our daughter – she is had a lot of issues with anxiety and school refusal for the last few years, and I wonder if had had the necessary information earlier like we did with our son, how much of a difference it would have made. (Although both are autistic, they present so differently it was not obvious.)

So I reiterate johnnyg’s exhortation to seek a diagnosis and early treatment if you suspect there may be autism at play. There’s a steep learning curve to getting your head around it and figuring out how to best help yourself and/or your loved ones, but you read hacker news, so you’re up for the challenge. Find (or start) a local community support group – it’s a hell of a lot easier than trying to hack it alone.