Older Parents and the “Risk” of Autism
April 8, 2007 by Kristina Chew, PhD
Filed under Health
Back in September a new study found that older dads are more likely to have an autistic child—-now, another study suggests that older mothers are also more likely to have autistic children. The study was conducted by researchers at Kaiser Permanente’s Division of Research in Oakland, California. Under lead author, epidemiologist Lisa Croen, the data of 132,844 single births at Kaiser Permanente hospitals in Northern California from 1995 to 1999 were analyzed. 593 autism diagnoses were found, of which 277 (47%) were autism diagnoses and 316 (53%) were PDD-NOS or Asperger’s diagnoses. Women had a 30% greater risk of having a child with autism if they were 40 and older (compared with women aged 25-29), athough the “increased risk” (to cite an April 2nd USA Today story) is “still very small: Only 1 in 123 children born to women 40 and older will have autism, compared with 1 in 156 children born to women 25 to 29.” Croen is quoted as saying:
“Older parents do tend to bring children to the doctor more often. When we controlled for these factors, we still found increased risk. Our data suggested that it’s not because older parents are more diligent about bringing their child to the doctor or more worried about the child’s development.”
The study concludes by stating that “If the relationship between parental age and ASD is causal, the fraction of autism in this sample attributable to having a mother or father older than 35 years is 4% to 13%.” It is published in the April Archives of Pediatrics & Adolescent Medicine.
I am never quite sure what to make of such findings: Will a message be sent out to the general public that one ought to “beware” of having children if one is 35 years or older? I can speak to the effects of such a study on older parents who have autistic children, as my husband Jim was an “older parent” when Charlie was born on May 15, 1997: Namely, studies such as these can lead a parent to blame him or herself and ask him or herself questions such as why did I wait…….what if I had not……etc.. It seems to me that it would be helpful if such results were reported with these effects in mind.
Another question for the study by Croen et al.: The children studied were all born at Kaiser Permanente hospitals in Northern California; what about children who were not born at Kaiser hospitals? Are some types of prospective parents, perhaps with certain socio-economic, educational, etc. backgrounds, more likely to have their children at Kaiser hospitals? Here I have to note that I have something of a personal association with Kaiser Hospitals myself, as my mother worked at one branch for several years, while my father worked at another branch part-time early in his career. Growing up, I mostly saw doctors and specialists at Kaiser (for the record, Charlie was not born at any of these hospitals…….he was born in a suburb of St. Louis, Missouri).
And also for the record—-as the study also noted an association between older maternal age and higher educational level—-I was 28 years old when I had Charlie and I am at such a “higher educational level.” One thing is for sure: Whatever the “risks” Jim and I may have been “in danger of” as regards having an autistic child, I am sure glad we have Charlie.
Is it over thirty or over 35 as a mother that they refer to you as a Prima Gravidas?
Prima Gravidas of the world, adjust your bifocals, reach out to the next Prima Gravidas’s walking stick to make a circle of united crumblies.
Best wishes
Found both ages referred to and also elderly prima gravidas.
Older, wiser, better.
It has been known for many years that having the first child after a certain age, usually 30 or 35, raises the risks for birth defects. The ages of the parents may very well play a huge role in many cases where a child develops autism.
I believe it is more plausible than vaccinations being the cause.
My dad was only 21 when I was born…regardless of whether older parents are more statistically likely to have ASD kids, the fact remains that *anyone* could end up with one of us.
Ahh, now I understand your reaction to my comment to someone else on a previous post.
And I profoundly hope you don’t mind the link because, even though you give a far more balanced view of things–including the possibility that the factors that influenced older parental age might be more relevant than the age, noting the study’s bias (to one hospital chain, in this case), raising questions of socio-economic factors, and acknowledging the value of people–the specter does still rise of ignoring the value of human potential, an unknowable, while considering the ‘costs’ of human difference or disability.
Your last sentence alone, including a conscientious use of quote marks, would (one hopes) cause people to think about how arbitrary such value judgments can be and how much real value might be lost if that’s not kept in mind.
Life without Charlie isn’t imaginable to me—I don’t know where I for one would be without him.
I am not stating that age is the only factor, but it has been a factor that hasn’t been given much attention,IMHO.
I find these studies curious as I was 21 when my (severely autistic) son was born. My husband was 30.
And yet, our daughter born ten years later exhibits no signs of being on the spectrum.
There is increased incidence in first born. Presumably that is an “environmental” factor and not a genetic factor. First time mothers are often really stressed out. Perhaps more so if they are very young, or very old.
If maternal “stress” were involved, this is what we would expect to observe.
I think they are also seeing the luck of the genetics “draw”.
daedalus2u, I had thought about the increased incidence in first born—–I never know what to make of these studies, as (within my range of acquaintances) there seems to be a thorough mix of parental age and of where a child occurs in the birth order.
I don’t know about that maternal stress theory either, daedalus. My first pregnancy was awesome. I was pregnant with my second son when my first was diagnosed. If stress could have been a trigger, he wouldn’t have stood a chance.
In any case, given my experience and that of several other young moms I’ve met through the years, it just seems very odd to me that this age things keeps popping up.
I just realized I didn’t specifically point out that my second son is not on the spectrum either.
I was refering to this study by Bauman.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=16134032&query_hl=11&itool=pubmed_docsum
They rank different stresses and compare them and it looks like there was a lot more “stress” in the ASD pregnancies.
lara, I found it odd too that parents’ age keeps coming up as a factor, rather as the “TV causes autism” theory has been.
Thank you for your interesting post!
I thought perhaps you may also find this related scientific study interesting to you:
Human Longevity and Parental Age at Conception
http://longevity-science.org/Parental_Age_2000.pdf