Autistic kids born preterm, post-term have more severe symptoms

April 3, 2012

For children with autism, being born several weeks early or several weeks late tends to increase the severity of their symptoms, according to new research out of Michigan State University.

Additionally, who were born either preterm or post-term are more likely to self-injure themselves compared with autistic children born on time, revealed the study by Tammy Movsas of MSU's Department of Epidemiology.

Though the study did not uncover why there is an increase in , the reasons may be tied to some of the underlying causes of why a child is born preterm (prior to 37 weeks) or post-term (after 42 weeks) in the first place.

The research appears online in the Journal of Autism and Development Disorders.

Movsas, a postdoctoral fellow in MSU's College of Human Medicine, said the study reveals there are many different manifestations of , a collection of developmental disorders including both autism and Asperger syndrome. It also shows the length of the mother's pregnancy is one factor affecting the severity of the disorder.

While previous research has linked to higher rates of autism, this is one of the first studies to look at the severity of the disease among autistic children who had been born early, on time and late.

"We think about autism being caused by a combination of genetic and ," she said. "With preterm and post-term babies, there is something underlying that is altering the of autism.

"The outside environment in which a preterm baby continues to mature is very different than the environment that the baby would have experienced in utero. This change in environment may be part of the reason why there is a difference in autistic severity in this set of infants."

Movsas added that for post-term babies, the longer exposure to hormones while a baby is in utero, the higher chance of placental malfunction and the increased rate of and instrument-assisted births may play a role.

The study also found that babies born outside of normal gestational age (40 weeks) – specifically very preterm babies – showed an increase in stereotypical autistic mannerisms.

"Normal gestation age of birth seems to mitigate the severity of autism spectrum disorder symptoms, and the types of autistic traits tend to be different depending on age at birth," she said.

The study analyzed an online database compiled by Kennedy Krieger Institute at Johns Hopkins University of nearly 4,200 mothers – with autistic children ages 4-21 – between 2006 and 2010. It divided the data on births into four categories: very preterm (born prior to 34 weeks); preterm (34 to 37 weeks); standard (37 to 42 weeks); and post-term (born after 42 weeks)

The mothers filled out a pair of questionnaires regarding the symptoms of their autistic children, and the results revealed very preterm, preterm and post-term autistic children had significantly higher screening scores for autism spectrum disorder than autistic children born full term.

"The findings point to the fact that although autism has a strong genetic component, something about pregnancy or the perinatal period may affect how autism manifests," said Nigel Paneth, an MSU epidemiologist who worked with Movsas on the paper. "This adds to our earlier finding that prematurity is a major risk factor for autism spectrum disorder and may help us understand if anything can be done during early life to prevent or alleviate autism spectrum disorder."

Explore further: Babies born just 2 or 3 weeks early at higher risk of poor health

More information: For the full research article, go to bit.ly/HRceAq

Related Stories

Babies born just 2 or 3 weeks early at higher risk of poor health

March 2, 2012
A research paper which demonstrates that babies born even just a few weeks early have worse health outcomes than full term babies has been published today in the British Medical Journal.

Recommended for you

Signaling pathway may be key to why autism is more common in boys

October 17, 2017
Researchers aiming to understand why autism spectrum disorders (ASD) are more common in boys have discovered differences in a brain signaling pathway involved in reward learning and motivation that make male mice more vulnerable ...

Whole genome sequencing identifies new genetic signature for autism

October 12, 2017
Autism has genetic roots, but most cases can't be explained by current genetic tests.

Mum's immune response could trigger social deficits for kids with autism

October 10, 2017
The retrospective cohort study of 220 Australian children, conducted between 2011-2014, indicates that a "an immune-mediated subtype" of autism driven by the body's inflammatory and immunological systems may be pivotal, according ...

Largest study to date reveals gender-specific risk of autism occurrence among siblings

September 25, 2017
Having one child with autism is a well-known risk factor for having another one with the same disorder, but whether and how a sibling's gender influences this risk has remained largely unknown.

Faulty cell signaling derails cerebral cortex development, could it lead to autism?

September 20, 2017
As the embryonic brain develops, an incredibly complex cascade of cellular events occur, starting with progenitors - the originating cells that generate neurons and spur proper cortex development. If this cascade malfunctions ...

Predicting atypical development in infants at high risk for autism?

September 12, 2017
New research from the Sackler Institute for Developmental Psychobiology at Columbia University Medical Center (CUMC) identifies a potential biomarker that predicts atypical development in 1- to 2-month-old infants at high ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

JVK
not rated yet Apr 04, 2012
Re: "something about pregnancy or the perinatal period may affect how autism manifests"
Is it not likely that intrauterine maternal-fetal chemical exchange followed by postnatal maternal-infant chemical exchange (via nutrient chemicals associated with pheromones that alter levels of luteinizing hormone and postnatal wiring and rewiring of sex differences in the brain) are the link to sex differences in ASDs? Does anyone else consider the role of olfaction in social behavior and sex differences in behavior in this context?

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.