Autism Studies You May Have Seen Recently and What to Know About Them
The causes of autism are largely unknown. According to the Centers for Disease Control and Prevention, 1 in 68 children are autistic; boys are more likely to be diagnosed than girls; and it affects all socio-economic statuses. With little known about it, an abundance of research about autism exists. It can be overwhelming to keep track of, and often these studies don’t take autistic individuals’ experiences into account or are rooted in finding a cure, versus bettering resources and therapies for people on the spectrum. In February alone, three stories based on research claims made headlines. The Mighty looked into each of these stories.
1. One study suggests a correlation between autism and ultrasounds.
On February 12, a new study about the possible link between autism and ultrasound usage during pregnancy came out. The study was published in JAMA Pediatrics by a team of researchers mostly from Boston Medical Center.
The researchers looked at images of ultrasounds from three groups. The first group was fetal ultrasounds of children who did not have any sort of developmental delay. The second group was ultrasounds of fetuses who were later diagnosed on the autism spectrum after birth. The third group consisted of children who had other developmental delays.
The study claimed women who had more scans or had scans that took more time were not more likely to have a child on the autism spectrum. But all the women in the study had at least five scans, whereas during non-high risk pregnancies only have two scans are typical. Nobody gets five scans unless there’s a suspected problem, Dr. Ahmet Bashat, director for the Center for Fetal Therapy at Johns Hopkins and did not work on this study, told The Mighty. The study was missing the information as to why these women had so many scans or what indicated these scans were necessary.
“They haven’t actually excluded that these patients may have had an indication to have these scans and it may also be that that indication itself maybe be related with autism,” Baschat said.
The only correlation between autism and ultrasounds they found was that women who had a higher depth of ultrasound penetration were more likely to have a child on the spectrum. The researchers defined the depth as the “distance between the ultrasound transducer (probe) on the skin and the point at what you’re looking at on the ultrasound,” Dr. Jodi Abbott, one of the study’s authors, told CNN.
According to Baschat, the depth is actually defined as the sound frequency. Ultrasounds generate a sound wave, which is reflected in the tissue and gives the image. A higher frequency means shallower depth into the tissue, and a lower frequency means a deeper penetration of the tissues. Many factors can affect what the depth needs to be to get a good image, such as placenta location and if the woman has a higher BMI, Baschat said.
The researchers had more women with a higher BMI in the autism group, which would mean a need for a deeper penetration in the first place, no matter if there was a subsequent autism diagnosis of the child. It would have been more reputable had the researchers cross-matched for BMI or had the same average BMI across the three groups of participants.
The study looked at the still images from the ultrasounds instead of the full video of the ultrasound. This could lead to sample error, Baschat said. Basically, a woman most likely had an ultrasound with varying depths throughout the procedure to look at certain parts of the fetus. The images may have been randomly captured at the deeper penetration, and there may have never been a difference in the depth across the groups of participants.
Also, the thermal index and mechanical index, both measures within an ultrasound that can actually affect tissue, including the fetus, were not different across the groups. Had these measures been different for the groups, that could have made more sense for the conclusion of a relationship between autism and ultrasounds, Baschat said.
“I’m skeptical,” Baschat said. “I think the methodology is not capable to support that conclusion.”
The International Society of Ultrasound in Obstetrics and Gynecology released a statement regarding this study, which the American Institute of Ultrasound in Medicine backed. The statement said there were many important limitations of this study not addressed in the paper. One such limitation is that the study characterized the depth of the ultrasound as a measure of ultrasound exposure. Exposure would actually be the thermal and mechanical index, which were not different.
“The most meaningful interpretation of these data should include consideration of the ultrasound safety indices, in particular the thermal index and mean duration of ultrasound,” the statement said.
The statement pointed out the dangers of broadcasting health messages that could affect many people and that the researchers and journal need to be held to the highest scientific standard. The statement alluded to the infamous, now-retracted study that caused immense harm by falsely stating vaccines cause autism.
Baschat said while you can’t exclude that there’s a possibility of an association between ultrasounds and autism, this study far from proves this.
“The benefit of a good quality ultrasound far outweighs what’s been reported here,” he said. “It would be a disservice [for high-risk pregnancies] to not go to an ultrasound because of the fear of that because you have a lot more to lose in that setting.”
2. One study hints at a possible autism diagnostic blood test.
Another study, published February 19 in “Molecular Autism,” suggests researchers have taken the first steps to having a possible diagnostic test for autism. Autism is currently diagnosed by clinicians based primarily on behavioral and social development assessments. A biological diagnostic test does not exist.
The study was conducted by a team of researchers from the University of Warwick in England and the University of Bologna in Italy. This study had a small size of participants (69 total; 38 on the spectrum), and the average age was 8 years old. The researchers analyzed blood and urine samples from each of the children. They found that children on the spectrum had higher levels of damage to certain proteins in the plasma compared to the control set of children.
After collecting the data, the researchers developed an algorithm based on the amino acids, the building blocks of proteins, found in the blood and urine to see if looking at protein damage was a way to create a valid diagnostic test for autism.
The test from the algorithm correctly identified 92 percent of the autistic children as being on the spectrum and 84 percent of children as not. This means 8 percent of those diagnosed with autism were not correctly identified by the test, and 16 percent of those who have never been diagnosed tested as autistic.
While this study is fairly sound in methodology, there are still limitations and drawbacks. This study has a small sample size, which would need to be much larger in future studies, which the researchers noted. The study only looked at children ages 5 to 12, and the researchers said the study would need to be duplicated with younger children to see if they can be correctly diagnosed using the same method. Also, the study only looked at children diagnosed with autism and those that aren’t. It did not have any way of specifying autism from other developmental or psychiatric conditions like ADHD.
While these results seem promising, nothing about diagnosing autism is going to change in the near future, a report published by the National Health Service in the U.K. stated. This study is simply a first step in furthering research on diagnosis.
The NHS report also stated that, “Media claims that this new test would help spot ASD early currently have no basis.” It is too soon to know if this would ever be used in clinical practice or improve upon current diagnostic methods through developmental assessments.
3. A (fake) study claims “Peppa Pig” causes autism.
A social media post went viral (again) this month, pointing to a study conducted at Harvard claiming “Peppa Pig,” a British cartoon on Nick Jr., causes autism. There was no such study done. The post was completely made up. This story needed to be addressed because, despite it being “debunked” in 2016, it is still making rounds online. The fact that this completely false, nonexistent “study” is still surviving after two years shows how hard it is to wipe away claims, especially about autism.
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