As though on cue

My, my, my.  I write a post that deals in part with vaccines and autism, and then look what the universe serves up.

Running a fever during pregnancy is associated with a risk of autism spectrum disorders and developmental delays in the offspring, a new study reports.

Previous research has suggested a connection between autism and various infections during pregnancy, including measles, mumps, rubella and influenza.

In the new analysis, researchers studied 701 children with autism spectrum disorders or developmental delays and 421 normal controls. After adjusting for age and other health and socioeconomic variables, they found that women who reported having had a fever during pregnancy were more than twice as likely as those who did not to have a child with a developmental disorder.

The study itself is behind a paywall, and it’s too cumbersome to look it up through my hospital accounts right now.  Thus, I can’t really comment with authority on its quality.  But that doesn’t stop me from having several thoughts.

First, even though this study is part of what appears to be an emerging picture about infections during pregnancy and autism risk, it’s still only one study.  It’s best that nobody panic just yet.

Second, would anyone like to lay odds about how the anti-vaccine movement will react to news that vaccine-preventable illness contracted during pregnancy might increase risk of autism?  Any guesses about the response to information that suggests vaccines might thus help prevent autism?  My bet?  Crickets chirping.

The truth is that we still really don’t know what causes autism.  The most exhaustively investigated possible link is with vaccines, and I don’t think I have anything further to say about that right now.  As with most disorders whose causes are described as “multifactorial” (translation: “we’re not sure”), I imagine it will probably be years before we have any solid evidence for the true source(s) of autism, if ever.

In the meantime, if you’re pregnant and get a fever, take some Tylenol.  (It seems to mitigate the risk.)  And don’t panic.  Everything will probably be all right.  It almost always is.

Russell Saunders

Russell Saunders is the ridiculously flimsy pseudonym of a pediatrician in New England. He has a husband, three sons, daughter, cat and dog, though not in that order. He enjoys reading, running and cooking. He can be contacted at blindeddoc using his Gmail account. Twitter types can follow him @russellsaunder1.


  1. I’d be curious to know if there’s any thought in the study to the causal arrow going the other way, i.e., that being pregnant with a kid with a neurodevelopmental disorder might make the mother more likely to get sick. I felt significantly different (worse) and was repeatedly sick during my pregnancy with a fetus with a neurodevelopmental disorder (which was not caused by conditions of pregnancy). Yes, I know how much an anecdote is worth, but I’ve since wondered if pregnancy with a disabled fetus affects the mom differently. I mean, it makes more sense that the virus (or fever) causes problems in the fetus rather than vice versa. But I wonder if they consider it.

    I hope you realize that this is just musing, and not my seeing the anti-vax light!

    • Seems to me that sort of musing is essential to the scientific process, Rose, even if the result reached is implausible. As our man Dr. Saunders says: “The truth is that we still really don’t know what causes autism.”

    • That is a really interesting thought, Rose. At the risk of being less-than-delicate, I wonder if the woman’s body can sense “problems” with the fetus and the sickness is a biological/evolutionary response intended to either end the pregnancy or signal to the woman that the pregnancy should be ended. This is not to say that I think such pregnancies should be ended.

  2. Interesting.

    Let’s think about this for a second. A mother who was ill during pregnancy (with a vaccine preventable disease), may be more likely to to give birth to a baby with a developmental delay. Ok. The mention of measles during pregnancy has been noted as being a possible factor (other studies and briefly mentioned in this story/research)… So, a mom who contracts measles during pregnancy, may have a risk… but a baby given a mmr vaccine (3 live virus vaccine, including measles)… that can’t be a factor? It’s impossible that this is an issue, right? Can measles (natural or vaccine strain) be a contributing factor, or not? Which is it? Get the story straight. Then, we move on to the “fever” aspect… A “fever” associated with an illness during pregnancy may be a factor. Of course, it is well documented that a “high fever” is very often noted as a vaccine reaction (not disputed as far as I know). No irony there, huh? Wow.

    I guess when the infant is developing in the womb they are possibly susceptible to these outside factors based on their mothers health… As soon as they pop out, they are instantly immune to all these external assaults on their system. Interesting how that works. 🙂

    Here’s a link for you brainiacs:

    • I’m going to assume that Russell is sick of this shit so that’s why he hasn’t answered. But, no, it’s really not the same sort of thing. By the time an infant is born the brain is mostly formed. There are a couple of “prunings” of neurons that happen, but I’m pretty sure that’s later than the typical age that autism is noticed.

      Look, I realize this is unlikely to sway you since at this point your belief in the vaccine hypothesis is basically religious in nature, but it was a decent hypothesis–as in plausible enough to warrant a good look–and that good look has been had. It just came up empty. It wasn’t stupid or unreasonable, but it also turns out not to be true.

      • I didn’t bother to reply to Mr. Schmoe’s comment because the holes in his thinking are so obvious I figured it wasn’t worth my time. He doesn’t understand the difference between infection with a wild-type pathogen and inoculation with a killed or attenuated version, he doesn’t understand the difference between in utero exposure to something and exposure as a child, he doesn’t understand how to read scientific studies (as evidenced by his comments on the earlier thread) if he even tried to read them as he avers.

        Plus, he links to Age of Autism, which is pretty much 100% comment fail in my book.

        • One of the issues that I find very often in this “controversy” is how usually intelligent people can be so sure of themselves when it comes to the safety of vaccines (and yes, it works the other way that some people won’t believe that ANY vaccines are EVER safe and effective). It’s as if people either forget or ignore the fact that with all medications / interventions there will be side effects and some people will be unable to tolerate these medications. Why do we give vaccines a free pass? This is especially important in this controversy because these are given to infants and are given as a preventative measure as opposed to a real medical intervention that needs to be given in order to treat an illness, etc… Some vaccines that are given are not worth the risk. Minimally, we should be spreading the vaccines out and not giving multiple vaccines at one time. If your child does react negatively, you have zero idea as to what they are reacting to.

          To say that you are open to the possibility (whether you specifically are or not, I don’t know… but it has been written about) that a case of the measles during pregnancy could impact the fetus neurologically but you couldn’t see how a infant say with a immature immune system, etc… could be negatively affected by the measles vaccine doesn’t make sense. Either the ability for the measles (or the measles vaccine) to trigger a reaction of some sort is either possible or it isn’t. Which is it? Please don’t tell me that the reaction can’t happen because it is a “killed or attenuated” version. That’s nonsense. Keep in mind the mmr vaccine is a three virus vaccine who knows what it can or cannot do. Maybe it’s the combination of the three viruses that is the problem in the system for some infants/babies. It’s as if doctors want it both ways…. If the vaccine works by being close enough to the actual virus to do it’s job in “protecting” the baby, then it also would carry some of the risk. YOU CAN’T HAVE IT BOTH WAYS. Which is it?

          The vast majority of babies handle vaccines fine. No issues. There is also a percentage of children who do not. Period.

          As for the link to Age of Autism. That was a ‘google alert’ that I received. The article is hilarious and sums it up perfectly. Doctors treat parents as if we aren’t intelligent enough to figure this out or to see that some babies do not do well with vaccinations. Trust me, I have doctor friends… let’s just say… some of them… Not all that intelligent and/or no common sense. Some of this requires an ability to use your common sense as opposed to reading books on Polio and/or listening to pharmaceutical reps or that God-awful Paul PrOffit.

          • Why do we give vaccines a free pass?

            We don’t. You and your ilk simply refuse to believe our answers.

            Which is it? Please don’t tell me that the reaction can’t happen because it is a “killed or attenuated” version. That’s nonsense

            No, it’s not. And your inability to understand how vaccines work is neither a problem you seem inclined (or capable) to fix nor a concern with which I can be bothered.

  3. Second, would anyone like to lay odds about how the anti-vaccine movement will react to news that vaccine-preventable illness contracted during pregnancy might increase risk of autism? Any guesses about the response to information that suggests vaccines might thus help prevent autism? My bet? Crickets chirping.

    I’d take that bet. If this study gains any public traction, the anti-vaxxers will respond with a reaction reminiscent of the Birthers confronted with actual Obama-was-really-no-shit-actually-born-in-Hawaii documents: outright denial, ad hominem attacks on the researchers, insistence that the research proves nothing based upon the identification of trivial imperfections (real or imagined) in the reports, and hints that the evil shadowy figures behind the massive fraud (Big Pharma in this case) have somehow engineered all this in an effort to Obscure The Sinister Truth.

    • Or, as we see here, “yeah sure maybe BUT YOU STILL CAN’T PROVE WE’RE WRONG!”

    • This is directed towards Russell…. (previous comment).

      “We don’t. You and your ilk simply refuse to believe our answers.”

      That’s because your “answers” don’t pass the smell test. The medical professionals aren’t able to tell us why children are sicker today than in years previous (by far…). But they KNOW that it isn’t due to vaccines? Really… that’s amazing! And yet, there are stories everywhere about illnesses / reactions post vaccination. Never mind the millions of dollars paid out by the government for vaccine injuries. We don’t trust you… because you don’t make sense. You are so intent on telling us (stupid parents) about how wonderful vaccines are that you missing out on some serious concerns on the topic. It is actually your inability to see what is happening around you that makes me (and others) trust you less.

      “No, it’s not. And your inability to understand how vaccines work is neither a problem you seem inclined (or capable) to fix nor a concern with which I can be bothered.”

      Oh, I may not be as “sophisticated” as you doc… you with your really cool piece of paper that proves how much smarter you are than me…. I get it. What did you spend 1 day or 2 on vaccines? How many hours did you put in at your fancy schmanzy medical school on the biological issues associated with autism. (ie gastro issues, autoimmunity issues, allergies, food intolerances)? And yes, I FULLY recognize that this is NOT the case with all those who are diagnosed with autism. I know that it is the case with many though… and those are the ones who may be the ones impacted negatively by too many vaccines.

  4. Why are you banning Joe Schmoe’s comments? 🙂

    • I’m not banning them. They got caught in the spam filter because of the link.

      And I don’t really care if Joe Schmoe comments. The poverty of his thinking is obvious enough at this point to make responding superfluous.

      • That suggests I’m destined to win our little bet — false claims of “censorship” are another favored tactic.

  5. Silly me… I should have realized that the link would get caught in the filter. Duh@me.

    I guess it is true that I am not as sophisticated as you!

    • I think you’re allowed one or two links but just not walls of them. Or maybe I get special treatment as I don’t often link too much, I often link all to the same site, and I’ve been around a bit. I just know I kinda went all spammy after Doc posted his stuff on the Hunger Games, a topic I’ve been kind prolific about.

  6. “In the meantime, if you’re pregnant and get a fever, take some Tylenol. (It seems to mitigate the risk.)”

    The study authors do not specifically recommend Tylenol. Only “antipyretics” or “fever reducers.” Ibuprofen use was also reported by the study participants, but it is unknown if one medication shows greater benefit than the other.

    As an aside, there are multiple lines of evidence that point to acetaminophen (aka Tylenol) as a possible autism trigger.

    It will be interesting to see how prospective studies on this play out.

    • I believe ibuprofen is generally not recommended during pregnancy, but you are correct that this study seemed to find a protective effect from antipyretics as a category, not just Tylenol.

      • You mean ibuprofen is not recommended during pregnancy and yet flu shots are? Why? Again, think this through. Why aren’t we using our common sense here.

        If I were to go to the pediatrician with a sick child… I would be surprised/shocked if he/she said…. Give your child this antibiotic along with ibuprofen along with some tylenol and add in some cough syrup and a baby aspirin all at the same time. They don’t do that. There would be very specific time frames. Specific instructions in timing. You would never give that many “treatments” at once. And yet, I could easily go to my pediatrician with my child and could be told: “Oh, you missed your well-baby visit last time… That’s fine, we’ll just catch up this time. It’s going to be 8 vaccines at once… but no big deal”.

        Where’s the common sense? Why do doctors not see this when it comes to vaccines? Are we so blinded by the good that vaccines can do that we lose track of the dangers?

        • I don’t know why I’m bothering, and I’m probably going to call it a day after this, but here goes.

          Ibuprofen isn’t recommended during pregnancy because of particular risks. Flu shots are to mitigate a completely different set of risks. We don’t recommend pregnant women consume alcohol or change the cat litter, but we do tell them to take folate. Your conflating of one set of recommendations and another is mere nonsense.

          I often do recommend an antibiotic along with a medication to control symptoms while the infection clears. I do this because I know how they all work, and which ones work well together and which do not. It is no different with vaccines.

          And for the very last time, at least from me, the questions about MMR vaccines have been asked and asked and asked, and they have been answered. I have provided numerous links in both my previous post and in comments to you directly. Just because you cannot understand the answers does not mean that they are not there.

          • “I do this because I know how they all work, and which ones work well together and which do not. It is no different with vaccines.”

            No studies to indicate safety of all vaccines given together. Just isn’t there. Sorry.

          • You and I are done. Comment further if you are inclined, but there is no point in my going to any further effort to engage with you.

          • Forgive my brother. You’ve been very patient.

            At what age do you think I should a parent first have his child leeched?

  7. So, Russell, at the risk of feeding the trolls, is it possible that the mother getting vaccinated at the wrong time of her pregnancy could cause autism? Is there any correlation with time of year of birth and autism that may coincide with the mother getting an annual flu shot, for example?

  8. So I imagine women who are more likely to pay attention to whether or not they run fevers during pregnancy are also more likely to seek help for any sort of abnormal behavior they see in their children. They therefore spend more time in doctor’s offices so they are more likely to see an autism diagnosis than women who don’t pay attention to their body temperature during pregnancy.

  9. The “fevers in pregnancy” study is another paper from the UC Davis CHARGE study, a long-term (It started in 2003), large N study (over 1,500 children and their families). The CHARGE group has published a number of papers that have been the subject of lousy science reporting (see the “close to freeways” study), but that doesn’t mean the underlying science is poor.

    How should parents respond to “X causes autism” reports? Emily Willingham (autistic parent of autistic kids, biologist, and editor of DoubleX Science) wrote This Just In: Being Alive Linked to Autism last year. The “X causes autism” breathless news reporting continued apace. Recently there was that “Could these 10 chemicals cause autism?” scare story, which prompted Dr. Willingham to write Science, health, medical news freaking you out? Take the Double-X Double Take First.

    The “freeway proximity” study (a previous CHARGE paper) was discussed at LeftBrain/RightBrain and Science-Based Medicine, both reliable sources of reporting on autism science.

  10. I dunno. I think it all boils down to what I want as a bumper sticker:

    Correlation =/= Causation

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