Featured Research

from universities, journals, and other organizations

Child's autism risk accelerates with mother's age over 30

Date:
April 22, 2014
Source:
Drexel University
Summary:
Older parents are more likely to have a child who develops an autism spectrum disorder than are younger parents. A recent study provides more insight into how the risk associated with parental age varies between mothers' and fathers' ages, and found that the risk of having a child with both autism spectrum disorder and intellectual disability is larger for older parents.

Older parents are more likely to have a child who develops an autism spectrum disorder (ASD) than are younger parents. A recent study from researchers from the Drexel University School of Public Health in Philadelphia and Karolinska Institute in Sweden provides more insight into how the risk associated with parental age varies between mothers' and fathers' ages, and found that the risk of having a child with both ASD and intellectual disability is larger for older parents.

Related Articles


In the study, published in the February 2014 issue of the International Journal of Epidemiology, researchers report that fathers' and mothers advancing ages have different impacts on their child's risk. The rise in ASD risk with parental age was greater for older mothers as compared to older fathers.

"The open question at hand really is, what biological mechanisms underlie these age effects?" said Brian K. Lee, PhD, an assistant professor in the Drexel University School of Public Health and research fellow of the A.J. Drexel Autism Institute, and senior author of the study. The observed differences in risk based on mothers' and fathers' ages point to a need to continue investigating underlying mechanisms of ASD that may be influenced by a mother's age, Lee said, even though much recent discussion has focused on fathers' and even grandfathers' ages.

The risk of having a child with ASD had a more complicated relationship to age in women than in men -- whose risk of fathering a child with ASD increased linearly with age across their lifespan. Among women giving birth before the age of 30, the risk of ASD in the child showed no association with age -- it was simply very low. But for babies born to mothers aged 30 and older, the chance of developing ASD rose rapidly with the mother's age.

Lee noted that the non-linear maternal age effect that is relatively stronger than the paternal age effect on ASD risk has been observed in previous studies, but has not received much attention.

Multiple mechanisms could be in play to account for the different patterns of risk, including environmental risk factors occurring in women after age 30. Factors such as complications in pregnancy could also underlie the effect of mothers' ages on a child's ASD risk but not a paternal age effect. The linear, steady increase in risk associated with fathers' ages is consistent with the hypothesis of increased genomic alterations over the father's lifespan that can increase risk of ASD, Lee said.

In this study, Lee and colleagues analyzed a large population registry sample of 417,303 children born in Sweden between 1984 and 2003, adjusted for numerous possible factors that could vary with parental age and also influence risk, such as family income and each parent's psychiatric history. The study also used a particularly comprehensive case-finding approach, to identify more ASD cases than other studies might, based on all pathways to care in a socialized health system.

A goal was to study these parental age effects in more detail by looking at possible differing risks of ASD with and without intellectual disability -- one of the most serious comorbid diagnoses with ASD, with a significant impact on functional status in life. This was the first population-based study with an ASD sample large enough to study ASD risk in populations of children with and without intellectual disability.

"When considering risk factors, we can't necessarily lump all ASD cases together, even though they fall under a broad umbrella of autism," Lee said. "We need to keep an open mind in case intellectual disability might be a marker of a different underlying mechanism."

The finding that ASD with intellectual disability had a stronger association with older parents, compared to ASD without intellectual disability, supports continued investigation of possible different mechanisms.

Lee noted that, although age effects are important indicators of risk at the population level that could eventually help researchers identify preventable causes of disability, they aren't very significant for a couple's family planning because the overall risk remains low. "The absolute risk of having a child with ASD is still approximately 1 in 100 in the overall sample, and less than 2 in 100 even for mothers up to age 45."


Story Source:

The above story is based on materials provided by Drexel University. Note: Materials may be edited for content and length.


Journal Reference:

  1. S. Idring, C. Magnusson, M. Lundberg, M. Ek, D. Rai, A. C. Svensson, C. Dalman, H. Karlsson, B. K. Lee. Parental age and the risk of autism spectrum disorders: findings from a Swedish population-based cohort. International Journal of Epidemiology, 2014; 43 (1): 107 DOI: 10.1093/ije/dyt262

Cite This Page:

Drexel University. "Child's autism risk accelerates with mother's age over 30." ScienceDaily. ScienceDaily, 22 April 2014. <www.sciencedaily.com/releases/2014/04/140422100025.htm>.
Drexel University. (2014, April 22). Child's autism risk accelerates with mother's age over 30. ScienceDaily. Retrieved April 1, 2015 from www.sciencedaily.com/releases/2014/04/140422100025.htm
Drexel University. "Child's autism risk accelerates with mother's age over 30." ScienceDaily. www.sciencedaily.com/releases/2014/04/140422100025.htm (accessed April 1, 2015).

Share This


More From ScienceDaily



More Mind & Brain News

Wednesday, April 1, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

AAA: Distracted Driving a Serious Teen Problem

AAA: Distracted Driving a Serious Teen Problem

AP (Mar. 25, 2015) While distracted driving is not a new problem for teens, new research from the AAA Foundation for Traffic Safety says it&apos;s much more serious than previously thought. (March 25) Video provided by AP
Powered by NewsLook.com
Smartphone Use Changing Our Brain and Thumb Interaction, Say Researchers

Smartphone Use Changing Our Brain and Thumb Interaction, Say Researchers

Reuters - Innovations Video Online (Mar. 25, 2015) European researchers say our smartphone use offers scientists an ideal testing ground for human brain plasticity. Dr Ako Ghosh&apos;s team discovered that the brains and thumbs of smartphone users interact differently from those who use old-fashioned handsets. Jim Drury went to meet him. Video provided by Reuters
Powered by NewsLook.com
Many Don't Know They Have Alzheimer's, But Their Doctors Do

Many Don't Know They Have Alzheimer's, But Their Doctors Do

Newsy (Mar. 24, 2015) According to a new study by the Alzheimer&apos;s Association, more than half of those who have the degenerative brain disease aren&apos;t told by their doctors. Video provided by Newsy
Powered by NewsLook.com
A Quick 45-Minute Nap Can Improve Your Memory

A Quick 45-Minute Nap Can Improve Your Memory

Newsy (Mar. 23, 2015) Researchers found those who napped for 45 minutes to an hour before being tested on information recalled it five times better than those who didn&apos;t. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins