Prenatal Ultrasound and Autism: Lack of Study

Caroline Rodgers, whose ideas I blogged about yesterday, wrote to me about lack of research on the possibility that prenatal ultrasound causes autism:

I have heard confidentially that applications for funding of prenatal ultrasound studies (not specifically investigating autism) have been repeatedly denied over the years — which helps explain the great paucity of safety studies, especially since the early ’90s, when the FDA approved an allowable eightfold increase in acoustic output. As recently as this year, funding was denied an ambitious, multi-site study that would have investigated if there was a relationship between ultrasound and autism.

In 2006 when Yale neuroscientist Pasko Rakic announced the results of his study that found prenatal ultrasound interrupted neuronal migration in mice in a way that was consistent with the brains of autopsied autistics, I was surprised that several scientists, including Rakic, did their best to downplay the results. At the time, Rakic was one of many of Autism Speaks’s scientific advisors.

I have spoken with various people throughout the NIH about my concerns [about ultrasound]. They all pointed to various large studies they believe are investigating ultrasound as a possible environmental cause of autism — most recently, the National Children’s Study and EARLI, but when I tracked down the study designs, it turned out that ultrasound is not being studied.

In a report at the time Rakic’s study was published, he indeed downplayed the results:

Dr. Pasko Rakic, chairman of the Yale department of neurobiology and leader of the study, was quick to offer parents reassurance about the safety of ultrasound — done for the proper reasons — in human pregnancies.

“If I had a daughter and she was pregnant, I would recommend she had it for medical reasons,” Rakic said.

Another researcher agreed:

“I couldn’t agree with him more,” said Dr. Joshua Copel, a professor of obstetrics, gynecology and reproductive sciences at Yale and spokesman for the American College of Obstetrics and Gynecology (ACOG). He was not involved in the study. . .

The researchers noted that mice are very different from humans, so the results of their study must be interpreted with caution.

“The forms of migration [of brain cells] and the timing of migration differ in primates like humans than in mice,” Copel said. “In humans, there is a much longer period in which neurons [nerve cells] are migrating.”

Does that sound “very different”?

Autism and Prenatal Ultrasound (more)

I blogged earlier about Caroline Rodgers’s idea that prenatal ultrasound may cause autism. She believes this idea isn’t getting the attention it deserves.

Recently she wrote to the head of Health and Human Services:

The latest autism prevalence figures released in December showed that while the overall autism rate increased more than 50% in the four years ending in 2006, there were significant differences across ethnic groups. White women had a much higher incidence of autism among their children than Black or Hispanic women. White mothers had 9.9 autistic children per 1,000, versus Black mothers who had 7.2 and Hispanic mothers who had 5.9.

There were also geographic differences. Among the 10 states with monitored sites, Alabama and Florida had the lowest autism rates, with averages of 4.2 and 4.6 per 1,000, respectively — far lower than the two states with the highest autism rates, Arizona and Missouri, which tied at 12.1 per 1,000. One interesting apparent statistical anomaly occurred among Alabama’s Hispanic population, which had a 68% decrease in autism while the overall national increase was 57%. In trying to understand why Alabama Hispanics had such a decrease in autism, I searched for evidence of public health policy changes. What I found was a surprise: according to a CDC multi-state surveillance report, Alabama and Florida were two of three states that had cutbacks in Medicaid funding for prenatal care during the time mothers in the study were pregnant. (The third state, West Virginia, was not among those monitored for autism in the latest study.)

Digging deeper, I turned up a CDC report on the timing of entry into prenatal care. The report showed that although most women started prenatal care in the first trimester, the percentages of both Black and Hispanic women who lacked early (first trimester) prenatal care were nearly twice that of White women . . . Over the span of the 10-year study, more women [in] all ethnic groups received early prenatal care, but the 2-to-1 ratio remained the same. . . .
Taken together, these three CDC reports tell a disturbing story: as more women . . . received more early prenatal care, the autism rate among their children increased, with those women receiving the most early prenatal care having the highest percentage of autistic children. . . .

A rigorous UC Davis study, published in January, of California children born between 1996 and 2000 identified 10 autism clusters . . . Highly educated women were much more likely to have children diagnosed with autism than parents who did not finish high school. In six of the clusters, the rate was as high as 4 to 1. Returning to the CDC Entry into Prenatal Care report, it is striking to note that in 1997 only 8.5% of pregnant women with some college education had delayed prenatal care, versus 29.9% of women who were not high school graduates — further [linking] early prenatal care [and] autism.

A study published in November on prenatal ultrasound trends from 1995-2006 found that the odds of a woman receiving an ultrasound during a prenatal visit nearly doubled over [those] 10 years. . . . The geographical and ethnic differences . . . dovetail with many of the geographical and ethnic differences found in the latest autism prevalence report. For instance, Southern women were 40% less likely to receive an ultrasound during a prenatal visit than Northeastern women, which could help explain why Florida and Alabama had the lowest autism rates among the states monitored. Also, Hispanics, who had the lowest overall autism prevalence rates in both the 2004 and 2006 CDC reports, were 20% less likely to receive an ultrasound during a prenatal than White women.

Not all the statistics available in these reports support the idea that prenatal ultrasound is causing autism. For instance, Southern states such as Georgia and North Carolina did not have low autism rates, but [perhaps this is because] the ultrasound trends study did not take into account “keepsake” ultrasound . . .

She also notes that a study by Yale neuroscientist Pasko Rakic “found that prenatal ultrasound disturbed neuronal migration in mice.”

Here is the broad argument. 1. Autism is correlated with wealth. It is absurd that autism causes wealth; it is unlikely that both are caused by something else. Thus this correlation makes it plausible that autism is caused by something that rich people have more of than poor people. Obviously rich people have more prenatal ultrasound. 2. A localized decrease in autism happened at the same time autism almost everywhere was increasing. At the same place and time prenatal ultrasound screening surely declined. This correlation is very difficult to explain with other ideas about what causes autism. Dozens of things (e.g., genes, diagnostic criteria) previously proposed as explanations of autism remained roughly constant at the same time as the decrease. 3. The mice data make the linkage considerably more plausible, assuming (a) the ultrasound dosage was reasonable and (b) humans with autism have unusual neural wiring that resembles the changes seen in the mice.

The full letter is on her blog. An article by Rodgers about this

Success with the GAPS Diet

Darrin Thompson writes:

Thanks for the pointer awhile back to the GAPS diet. It caught my eye and my wife and I implemented it for us and our autism kids. After about a month we are experiencing marked reductions in psoriasis and allergy symptoms. Our 3 autism kids are [now] doing well with no huge barrages of expensive vitamin supplements. We’re keeping up only with Vitamin E, DHA and eventually selenium. We’re noticing improvements in their communication skills.

Assorted Links

Thanks to Vic Sarjoo, Anne Weiss, and Marian Lizzi.

A GAPS Testimonial

Gut And Psychology Syndrome (GAPS) is a book by Natasha Campbell-McBride about how to treat allergies, autism, and similar conditions. In this entry, Cheeseslave talks about her own son and then quotes another mother about the effects of the GAPS diet (plus other changes) on her autistic son.

Kevin lacked oxygen at birth, so in the first year of life, I already saw that he was not developing like my other kids (he is our 5th). His motor skills lagged and he cried a lot, didn’t sleep so well, etc.At two, his behavior was just not right. He never responded right to correction, would throw things in anger or frustration, cried all the time, especially when waking up, basically never happy. He didn’t walk until two and then he would fall down constantly.

He also began to always be starving. When he was really hungry, his face would get distorted and frozen in a strange way. I now think he was having seizures of sorts.

We did not vaccinate at all and we figured out that if we fed him lots of protein type foods like meats, he would relax his body and face and be able to go play for a bit until it happened all over again in a short time.

I do think that because we didn’t vaccinate and figured out to keep feeding him this way, we were able to “coast along” like this for years. He had learning disabilities, lacked social skills and continued to have autistic traits like sensory issues, hiding under blankets, reacting to sounds, not liking people around, rigid in routines, and spinning and going on his head along with head banging.

Long story shorter, we did get a diagnosis of Aspergers at one point. We took him to doctor after doctor, specialist after specialist to no avail. He also strangely was NEVER once sick (we later learned that his immune system was not working a bit).

At 9 years old, he got pneumonia, followed by asthma and allergies. His eating [problems] had escalated to the point of feeding him every 20-30 minutes or he would have gigantic meltdowns. We eventually could not even have people over.

He was given an inhaler for the asthma and suddenly, without us making the connection, he began to not respond when called, became extremely hyperactive and began to run away at all hours of the day and night requiring police to find him and being very dangerous. (we once lost him in the middle of downtown Chicago). He would also try to jump out of moving vehicles, out of windows and required constant restraining.

The seizures got bad, he would fall down the stairs and lose consciousness several times per day. They tried psych drugs and he almost died twice from his reaction to them (I am now grateful that we couldn’t go that route).

We became so desperate that we brought him home from hospital and got deadbolts to keep him from running, did all our own restraining and called alternative docs to help us.

We began kefir and diet from nutritionist (basically a BED [Body Ecology Diet]/GAPS version), took him off inhaler. His allergies were totally out of control, he could barely open his eyes from swelling, and his chin was deformed and swollen, his belly too, his whole body. He would only eat junk food and fast foods and it was incredibly difficult to transition him to the diet.

The DAN (Defeat Autism Now) protocols we followed, made him worse in lots of ways b/c the chelation made him extremely violent, the B12 shots kept him awake for nights on end without any sleep, the antifungals and all those other interventions were nightmarish for him.

Eventually, I resolved to use only foods and do this without any kind of doctors. So for this past year, I researched and researched and was determined to bring him back from this state. We have done a combo of GAPS (and BED) very successfully along with lots of fermented foods and drinks.

The allergies and asthma are 100% gone, the seizures we have had only one in 65 days and very mild (compared to 5-10 per day). He sings every morning and has cried once in the last 2.5 months (he used to cry for 1-3 hours at a time each day) and he can go outside again without running away. He is in martial arts, acting appropriately at church, having eye contact, no autistic traits of late and learning academics after two years of not being able to open a book. He reads before bed at an 8th grade level.

This story has many interesting elements. 1. Huge improvement. Very plausible that it’s due to the dietary change. 2. Autism and allergies go away at the same time, suggesting same cause. 3. Treatment with fermented foods. 4. A different “radical” solution failed, meaning there is no reason to think this is a placebo effect. 5. The mystery of why an inhaler made things worse. 6. Autism not due to vaccination.

Does Prenatal Ultrasound Cause Autism?

Caroline Rodgers, a science writer, has noticed some very interesting correlations:

The new autism figures published in the CDC’s 12-18-09 Morbidity and Mortality Weekly Report (MMWR) https://bit.ly/57XRca reveal an apparent anomaly: While there was an overall average autism increase of 57 percent in children born between 2002 and 2006, Hispanics in Alabama showed a 67 percent decrease in autism.

The mothers of the first batch of children who were eight years old in 2002 would have been pregnant in 1993. Therefore, I looked at what changes might have occurred in Alabama’s public health policy in 1993 that would explain a 67 percent drop in the autism rate of Hispanic children born between 2002 and 2006.

According to the 2002 PRAMS Surveillance Report: Multistate Exhibits Medicaid Coverage for Prenatal Care https://bit.ly/8godkv .

During 1993-2002, the prevalence of Medicaid coverage for prenatal care . . . decreased in 3 states (Alabama, Florida and West Virginia).

This particular correlation is in addition to a broad correlation between wealth and autism (more wealth, more autism):

Also significant in last week’s MMWR report were the ethnic differences in autism prevalence found among non-Hispanic whites, blacks and Hispanics. The autism rate in the monitored areas throughout the United States of children of non-Hispanic white women was 102 per 10,000; among black children, 76 per 10,000; and among Hispanic children, 61 per 10,000 — roughly half of the non-Hispanic white rate. These results seem counter-intuitive, since the non-Hispanic white population could be expected to have more access to prenatal care than the black or Hispanic populations. Yet if autism risk is increased by exposure to prenatal ultrasound, these figures make perfect sense.

This isn’t cherry-picking. Rodgers believed that we should take seriously the idea of a prenatal-ultrasound/autism link based on entirely different data.

Interview with Tyler Cowen

Tyler Cowen’s new book Create Your Own Economy: The Path to Prosperity in a Disordered World has a lot to say about two topics in which I am especially interested: autism and human diversity. What can the rest of us learn from people with autism? What does the wide range of outcomes among autistic adults tell us about our world? I interviewed Tyler by email about his book.

ROBERTS If I remember correctly, you think a book should be new, true, and something else. What’s the something else?

COWEN The “something else” should cover at least two qualities.

First, if everyone read the book and was persuaded by it, would anything change for the better? An author should aim to write a book which matters.

Second, the book should reflect something the author really cares about. If the author doesn’t care, why should the reader?

ROBERTS What was the tipping point for this book — the event that made you say: I’m going to write a book about THIS?

COWEN To me it’s very important what an author is thinking about in his or her spare time, if the phrase “spare time” even applies to my life, which has an extreme blending of work and leisure time. Ideally that is what an author should be writing about. At some point you realize: “Hey, I am constantly thinking about xxxxx in my spare time!” And then you want to write it up.

I also hit up the idea of this book through pondering the lives of some particular individuals I know — and how much they *live* the thesis of my book — although I am not sure they would wish to be identified publicly.

ROBERTS Have you been to Autreat, the annual conference of Autism Network International, that you mention? If so, did it affect your thinking?

COWEN I haven’t been to Autreat, which for me is located somewhat inconveniently away from major cities (that is on purpose, I believe). I’m also not clear on exactly who is welcome, who needs an invitation, etc. Most conferences have a very high variance in quality across presentations and mostly one goes to meet one or two key people; often you don’t know in advance who they will be. I suspect the same logic applies to Autreat as well.

ROBERTS Do you think there are jobs that persons with autism do better than persons without autism?

COWEN Autistics often exhibit superior skills in attention to detail, pattern recognition, what I call “mental ordering,” and they have areas of strong preferred interests, in which they are very often superb self-educators. So yes, that will make many autistics very good at some jobs but also poorly suited for others. But I don’t want to generalize and say “autistics are better at job X,” that would be misleading. Across autistics there is a wide variety of cognitive skills and also problems. Engineering and computer science are the stereotypical areas where you expect to find higher than average rates of autism. While I suspect this is true in terms of the average, it can be misleading to focus on the stereotype precisely because of the high variance of skills and outcomes among autistics. One of the central issues in understanding autism is grasping the connection between the underlying unity of the phenomenon and the extreme variability of the results. In the short run, positive stereotypes can perform a useful educating function. But the more we present stereotypes, the more we are getting people away from coming to terms with that more fundamental issue, namely an understanding of the variance.

ROBERTS There is a basic biological phenomenon in which animals and plants under stress become more variable. Some say variability in the genotype has been released into the phenotype. Do you think the variance seen in autism has been “released” in some way?

COWEN I am not sure I understand the question…for one thing I am not sure what is the postulated increase in genetic stress…

ROBERTS Yes, it’s a confusing question. Let’s try this: What do you think the high variance of outcome seen in autism is telling us?

COWEN I’ll try to make that more concrete. One view of autism is that autistics have greater access to lower-level perception and such that access is essential for understanding autism. On one hand it gives autistics some special abilities, such as pattern recognition, certain kinds of information processing, and noticing small changes with great skill. (In some cases this also leads to savant-like abilities.) This also may be connected to some of the problems which autistics experience, such as hyper-sensitivities to some kinds of public environments.

It could be that non-autistics have a faculty, or faculties, which “cut off” or automatically organize a lot of this lower level perception. The implication would be that for autistics this faculty is somehow weaker, missing, or “broken.” The underlying unity in autism would be that this faculty is somehow different, relative to non-autistics. The resulting variance is that the difference in this faculty gives rise to abilities and disabilities which very much differ across autistics.

That’s one attempt to come to terms with both the unity of autism and the variance within it. It’s a tough question and we don’t know the right answer yet, in my view. What I outlined is just one hypothesis.

ROBERTS A clear parallel in the increased variance of autistic persons is the increased variance of left-handers. Left-handers have brain organizations that vary much more than the brain organization of right-handers. Right-handers are all one way; left-handers are all over the place. Do you see any similarities between left-handers and persons with autism?

COWEN I recall some claims that autistics are more likely to be left-handed but I’ve never looked into their veracity. There are so many false claims about autism that one must be very careful.

ADHD is another example of something which produces high variance outcomes. I don’t think it is correct to call it a disorder *per se*.

We’re just starting to wrap our heads around the “high variance” idea. Most people have the natural instinct to attach gross labels of good or bad even when a subtler approach is called for.

ROBERTS The term left-hander is confusing because left-handers aren’t the opposite of right-handers. The dichotomy is okay but the two sides are better labeled right-handers and non-right-handers. In other words, one group (right-handers) has something (a certain brain organization); the other group doesn’t have that brain organization. Then the vast difference in variance makes sense. How accurate would it be to say that non-autistics have something than autistics don’t have? (I’m left-handed, by the way.)

COWEN I would say we still don’t have a fully coherent definition of autism. And “have” is a tricky word. I think of autistic brains as different, rather than “normal” brains with “missing parts.” Some researchers postulate differences in the kind of connections autistic brains make. In thirty years I expect we will know much, much more than we do right now.

ROBERTS I hope this isn’t too self-indulgent: What do you make of the correlation between autism and digestive problems?

COWEN I don’t think there are convincing theories about either digestive problems causing autism or autism causing digestive problems. There is *maybe* a correlation through a common genetic cause, but even if that is true it is not very useful as a means of understanding autism. This is another area where there are many strong opinions, often stronger than are justified by the facts.

ROBERTS Another “assorted” question: I loved the study you mentioned where people with perfect pitch were more likely to be eccentric than those without perfect pitch. That’s quite a result. How did you learn about it?

COWEN There is a somewhat scattered literature on music, cognition, and society. It still awaits synthesis, it seems. Someone could write a very good popular book on the topic. (Maybe Gabriel Rossman is the guy to do it.) The more I browsed that literature, the more interesting results I found.

ROBERTS I don’t think I’ve done justice to your extremely original book but here is a last question. You talk about Thomas Schelling’s use of stories. Presumably in contrast to other econ professors. I think of story-telling being something that once upon a time everyone did — it was the usual way to teach. Why do you think Schelling told stories much more than those around him?

COWEN Thanks for the kind words. Schelling has a unique mind, as anyone who has known him will attest. I don’t know any other economist or social scientist who thinks like he does, but we’ve yet to figure out what exactly his unique element consists of. I would say that Schelling views story-telling as a path to social science wisdom. They’re not even anecdotes, they’re stories. Maybe that doesn’t sound convincing to an outsider, but it got him a Nobel Prize.

I am very interested in the topic of “styles of thought in economics.”

Autism and Digestive Problems

The latest issue of Pediatrics has a study that asks whether autism is associated with digestive problems. The authors compared the medical records of about 100 autistics with about 200 matched controls. The controls came from an area in Minnesota, near the Mayo Clinic, in which almost everyone has a health record on file that the researchers could look at. So the controls are a good sample of the non-autistic population.

The New York Times described the results like this:

The scientists found no differences [should be difference, singular] in the overall frequency of gastrointestinal problems reported by the two groups.

This isn’t quite right. The study found that the proportions of persons in each group to have had at least one digestive problem by age 20 weren’t reliably different. For the autistic kids, the proportion was 77%; for the controls, 72%.

The study design seems fine but the data analysis has a lot of room for improvement. You have an idea you want to test, good; try to test it with one test. The authors boiled down all their data into “at least one problem by age 20″ — that’s just what epidemiologists are told to do — but this was a poor choice. First, there is a ceiling problem. If both groups had percentages in the 90′s, this would be obvious. Better to avoid the ceiling problem. Second. to combine different symptoms with the “at least one” rule is likely to be less sensitive to differences than a combination rule that takes amount into account. The analysis in the article treats someone with 1 problem as equal to someone with 50 problems. No justification is given. Third, it isn’t obvious that it makes sense to combine symptoms this way. What if Symptom 1 and Symptom 2 are uncorrelated? In other words, what if whether you have Symptom 1 doesn’t affect your chances of having Symptom 2? Then to combine them (as the authors do) makes no sense. Factor analysis is how you condense several correlated measures into a few uncorrelated measures.

The study separated digestive problems into five categories (constipation, diarrhea, and three others). In each of the five categories, persons in the autistic group were more likely to report the problem than persons in the control group; in four of the five categories, the difference was significant (with one-tailed p values; the authors misleadingly use two-tailed p values — without making that clear). In one of the five categories the difference isn’t anywhere close to significant — which supports the idea that that there are at least two dimensions here: one on which the two groups differ, and one on which they don’t.

In the discussion, the authors, not realizing that four out of five of their problem categories differed significantly in the predicted direction, try to explain away the two differences that were significant with two-tailed p values: in constipation and picky eating. They note that autistic children get more medication that normal children. “Many children with autism are treated with resperidone, and this may result in increased appetite and weight gain,” they write. Why a drug that causes weight gain would cause picky eating isn’t explained and, without explanation, doesn’t make sense. Weight gain — they mean too much weight gain — involves eating too much; picky eating involves eating too little. Nor do the authors explain why their results differed from many previous studies. My take on the paper is that their results confirm previous studies, so that would have been interesting to read.

The Mother of an Autistic Child Writes…

Lisa Belkin, who blogs about parenting for the NY Times, prints an excellent letter from the mother of an autistic child about what it is like:

“Crying.” The study talks of the crying. [The mom wrote to Belkin to complain that a study Belkin described sugar-coated things.] The word pales in the face of our son’s dissolutions into tears. These days, if he hears a simple “no” or learns of some change in plans, he might launch into a 10-minute jag, where he argues fiercely with us in between the sobs. Then he can quickly escalate to ear-piercing screams lasting another 15 minutes or more. It’s a wonder none of our neighbors have misconstrued what they might have heard and called 911. The shrieking does subside, back into sobs, and that part is somehow harder to watch, reminding me how terrifying it must be to feel to be that out of control, especially when you’re a small, anxious child.

No good deed goes uncriticized. An autistic adult named Sarah writes to Belkin to complain:

Please, consider that autistic people read blogs and have feelings as well. Your blog entry claims to show “the unvarnished reality of autism,” but the feelings and perceptions of actual autistic people are sadly missing from your account.

What an idea: that no blogger should write something that might hurt the feelings of someone with autism. As for the “sadly missing,” the passage I quoted from the mom describes the “feelings and perceptions” of an autistic person at length. Sarah blogs here.

Refrigerator Parents

Two epidemiological case-control surveys have linked the age at which, growing up, your home got a refrigerator with your chances of getting Crohn’s Disease later in life. The controls (without Crohn’s) got refrigerators later than the cases (with Crohn’s). This is not one of those data-mining correlations. It was (a) predicted and (b) found in two independent studies.

Crohn’s Disease is much more common in rich countries than poor ones so it was reasonable to examine aspects of lifestyle that distinguish rich and poor countries. In rich countries, the likelihood of having Crohn’s seems to be increasing over time, which is more reason to look for environmental explanations. One of the studies was done in Tehran, where a significant fraction of the population didn’t have a refrigerator when they were born. The control group was patients with irritable bowel syndrome, a curious choice. (The differences might have been larger had they chosen a non-inflammatory digestive problem.) The other study was done in England and used a control group of patients with a non-inflammatory disease.

Refrigerators, of course, retard the growth of bacteria, which I believe everyone needs to eat plenty of (the umami hypothesis). Long ago, “ refrigerator mothers” — mothers who treated their children with insufficient warmth — were blamed for autism and schizophrenia in their children. Now that it is clear that autism is connected with digestive problems there may be ironic truth in the old claim.

Thanks to Dennis Mangan.

Refrigerator poetry.