Very low birth weight children more likely to show early signs of autism

[dyslimbic]

http://www.medscape.com/viewarticle/572735

April 9, 2008 — In a recent study of 91 toddlers who had been born prematurely and weighed from 1 to 3.28 pounds (460-1490 g) at birth, 25% screened positive for early signs of autistic features.

This study is the first to document a high prevalence of early autistic features in survivors of extreme prematurity, the group, led by Catherine Limperopoulos, PhD, at McGill University, in Montreal, Quebec, Canada, writes. The toddlers were screened at a mean age of 21.9 ± 4.7 months with use of the Modified Checklist for Autism in Toddlers.

The findings suggest "routine, systematic screening of very-low-birth-weight infants for early signs of autism is important," Dr. Limperopoulos told Medscape Psychiatry. "It's [also] important to perform formal diagnostic autism testing in those who test positive, in order to confirm whether this initial positive screening does in fact translate into autism spectrum disorders," she said, noting that the team is currently performing these definitive follow-up tests for autism in this cohort.

The study looked at an extremely high-risk subgroup of premature infants with a gestational age range of 23 to 30 weeks (and did not include premature infants having a gestational age of 31 to 37 weeks), she added.

The study is published in the April issue of Pediatrics.

Advances in neonatal intensive care have dramatically increased the survival of preterm infants, but there is an increasing population of very-low-birth-weight children that experience significant disabilities in socialization, communication, and behavior, the group writes.

The study was prompted in part because the team had clinically observed that some very-preterm infants displayed unusual social behaviors at follow-up visits. In addition, validated screening tests to detect early signs of autism have now become available.

Recent studies have demonstrated benefits from intense early interventions, and the American Academy of Pediatrics is endorsing autism screening for all children by age 2 years, Dr. Limperopoulos noted.

The team aimed to perform autism screening tests on toddlers who had been born prematurely and had a very low birth weight and to identify risk factors associated with a positive screening result.

They studied 91 consecutive preterm infants with a birth weight of less than 3.3 pounds (1500 g). When the infants were between 18 and 24 months old, adjusted for prematurity, they were tested with the Modified Checklist for Autism in Toddlers (a 23-item "yes/no" parent report checklist to detect early signs of autism at 16 - 30 months).

The children were also tested with the Child Behavior Checklist for ages 1.5 to 5 years (a caregiver questionnaire about behavior and emotional problems in young children) and the Vineland Adaptive Behavior Scale (a measure of a child's functional status in a wide range of skills).
One Quarter Screened Positive

Of the 91 infants, 23 (25%) had a positive score on the Modified Checklist for Autism in Toddlers screening test. Having abnormal scores on this test correlated highly with having internalizing behavioral problems according to the Child Behavior Checklist and having socialization deficits according to the Vineland Adaptive Behavior Scale.

The infants were more likely to screen positive for early signs of autism if they had the following risk factors: male sex, abnormal results on magnetic resonance imaging (MRI) studies, lower birth weight, younger gestational age, maternal infection, maternal acute intrapartum hemorrhage, and more severe illness at birth.
What Does this Mean?

"Early autistic behaviors seem to be an underrecognized feature of very low birth weight infants," the group concludes. "The results from this study suggest that early screening for signs of autism may be warranted in this high-risk population followed by definitive autism testing in those with positive screening results."

Larger, prospective studies are needed to corroborate these findings and to determine to what extent this initial positive screening test result is a transient or emerging finding during a time of critical development, Dr. Limperopoulos added.

This study was supported by grants from the National Institutes of Health, the LifeBridge Fund, the Caroline Levine Foundation, the Trust Family Foundation, and the Canada Research Chairs Program. The study authors have disclosed no relevant financial relationships.

Pediatrics. 2008;121:758-765.



*
Clinical Context

There is strong evidence of neurodevelopmental impairment among infants with a history of preterm delivery. A study by Hack and colleagues, which was published in the January 17, 2002, issue of the New England Journal of Medicine, observed a cohort of 242 very-low-birth-weight infants into adulthood to assess outcomes. Compared with infants delivered with a normal birth weight, fewer subjects with a history of very-low birth weight had graduated from high school or were enrolled in college. Very-low-birth-weight participants demonstrated lower academic achievement and intelligence scores, and they also experienced higher rates of neurosensory impairments and subnormal height. At the same time, the very-low-birth-weight group reported less alcohol and drug use and had lower rates of pregnancy than normal-birth-weight controls.

A history of prematurity and low birth weight has also been associated with an increased risk for autism spectrum disorders. The current study examines the prevalence of a positive screening for autism disorders among infants with a history of prematurity as well as factors associated with a positive screening result.

[Kristen (ColeysMom)]

There is currently a program in the US that automatically follows low birth weight babies closely through age 3. Coley aged out before any modifications were made to that but last I had heard there was a study that showed that developmental/learning difficulties persist into adulthood so they were 'considering' extending the 'follow-up'.

When the program was designed, it was in response to a study that concluded that preemies 'out-grow' their prematurity issues (developmental and growth) by 3, WITH assistance. This is false, not sure if there was an error in that original study, or if it's because when the study was done most preemies didn't survive before a certain gestation. Maybe some combo.

The age of viability is now at about 21 weeks. Because of that they have several classifications for premature babies now. Pre-term, premature, very premature and extremely premature. These are actual medical terms. Coley fits into the extremely to very. But the definitions vary a bit because they haven't decided whether it is a weight marker or a gestation marker, so depending on which definition is used he moves between the 2. As you can see from the 2 studies that were posted on this recently, one talks about gestation and the other about weight.

The reason for this is that babies can also be SGA (small for gestational age) and then there is also IUGR (intra-uterine growth restriction) where babies can have trouble getting nutrition to grow and are delivered early intentionally because they are in danger of starving.

So blah blah blah...all that was to just let you know that that program that is in place has 2 roles, one to collect data, but the other is to act as the 'at risk' coordinator of services up to age 3. It's called 'at risk' because it includes all of those categories, plus a few others. This same program also dictates that just because the child falls into the 'high risk' category that regardless of their screening with EI that they receive services through 3.

We are lucky that this is the case because Coley did well, aside from his GI issues, until he hit about 1yo (which would have been 9 months adjusted) that's when his developmental issues began to surface. But because of the program he had been reciving EI services from discharge out of the NICU, plus was followed by the at risk team.

So, take some comfort in knowing that while more than 1 out of every 8 children are born premature, and even more fall into the high risk group...that there is a program to make sure that they do not 'fall through the cracks' and hopefully that program is getting bigger & stronger now!

Also, it's worth mentioning too that preemies are born with immature neurological systems. Drs are still trying to figure out if the immaturity is what 'looks like' an ASD or if it's an actual ASD and may help provide insight for non-preemies that fall on the spectrum.

The problem is that preemie brains are not fully developed (neither are their guts or their immune systems btw) and as you know when you 'learn' you hard wire something. Well once the brain starts seeing, hearing, feeling, experiencing, it starts to solidify connections...well in a brain that hasn't fully developed they are seeing loads of 'confusing' wiring. This is the basis of the preemie sensory integration disorder (it's called something else now though right?)...there is a different theory as to why kids on the spectrum have sensory issues. Course it's all theory...but the fact does remain that much of what the preemie is struggling with is a body that is not prepared to be functioning, yet needs to be.

They are finding now that it doesn't fully develop by 3, AND that it may not develop 'typically' ever, because it's development was hampered by use. This atypical development may or may not mirror a similar issue going on with kids that are not premature (or at risk) but in many cases the overt symtoms look very similar to disorders on the spectrum.

So it's worth keeping up with the preemie developments as they contribute information toward ASDs. It's good to know too that the March of Dimes is a HUGE supporter of research and advocacy for preemies and the causes of prematurity...so there is loads of $$$$ going into awareness and research. Infact they may even be the backers of the follow-up program, not sure.

Here is MOD's website if you'd like to take a peek, there's loads of info, articles and statistics: http://www.marchofdimes.com/peristats/?gclid=CJWbr4PH0JICFRE0FQod3HcWIA

I'm not sure anyone actually cares about all this, but thought I'd throw it out there just in case.

[dyslimbic]

I am sure people will find what you wrote of interest Kirsten. Not having any family history of autism(though i suspect i may have some nvld traits ie verbal-performance gap,poor visual spatial skills,executive functioning/critical thinking issues and not very good when it comes to practical tasks etc) i am a dunce when it comes to autism.
I just post the occasional thing i find in the hope it's of interest/helps.

[The Pogue]

It is interesting, thanks Dyslimbic.

Premature brains are vulnerable to a huge away of insults, which can lead to many conditions and disabilities. As the survival rate of these tiny babies goes up, so too do the rate of complications.

[mom2nfautism]

I can say its true. My children both have neurofibromatosis which predositions childrend to having ADHD, and Autism then both were also premature.

My 13 y old daughter was born at 30 weeks (3 mo early) and weighed 2lb. 4oz and my youngest daughter is 11 and was also born at 30 weeks (3 mo early) and weighed 2lb 10oz.

They both recieved early interviention and thereapys and school at age 3 etc. so they had two things that they say can cause autism.

Neurofibromatosis is one of the genetic disorders they are linking to autism .. i have several books that list neruofibromatosis as a cause and some that say neurofibromatosis predostions children to having it.

And then the prematrueity that they are now linking.

Bea