6 ms·

Does Acetaminophen During Pregnancy Increase Autism Risk? A Look at the Evidence

6 points by uws 1y ago

vixen99 1y ago
'Evidence That Acetaminophen Triggers Autism in Susceptible Individuals Has Been Ignored and Mishandled for More Than a Decade' https://www.preprints.org/frontend/manuscript/a6a26b165faf5e655587c37348d84f11/download_pub https://www.preprints.org/frontend/manuscript/a6a26b165faf5e... 'Overwhelming evidence shows that exposure of susceptible babies and children to acetaminophen (paracetamol) triggers many if not most cases of autism spectrum disorder, and that oxidative stress causes susceptibility. However, these conclusions have not yet been widely acknowledged or integrated into clinical practice or regulatory guidelines'
- IAmBroom 1y ago
  "Not peer-reviewed version" I too can self-publish anything I want. Would you like to know more about how my kool-aid recipe blocks lizard people brain control?
eterm 1y ago
In the words of the UK health secretary: > don’t pay any attention whatsoever to what Donald Trump says about medicine Source: https://www.theguardian.com/politics/2025/sep/23/wes-streeting-rejects-trump-claim-linking-paracetamol-and-autism https://www.theguardian.com/politics/2025/sep/23/wes-streeti...
potatototoo99 1y ago
Unfortunately, with Trump politicizing this so much, the waters are very muddy now on any research on this coming from the US. I'll wait for the EU/Japan researchers' review.
- maxerickson 1y ago
  How does Trump saying something muddy what scientists and doctors are saying? Even if he wasn't self serving and incurious, his statements wouldn't be worth more than the actual science.
  - potatototoo99 1y ago
    If your question is in good faith, US researchers work on US universities and research institutes, both partly sponsored by the US government, who is very vocal on what it thinks the scientific opinion should be. And this new study is a meta study only (at best), very subject to interpretation by what I skimmed.
    - maxerickson 1y ago
      The president is an idiot and RFK is a grifter crank, I don't have to take them seriously just because they have power. Also, it's against the guidelines to say things like "If your question is in good faith".
      - IAmBroom 1y ago
        OK, but the response still answered your question: Trump and his cronies get to pick and choose which research gets funded and publicized through government channels.
ben30 1y ago
The political circus is drowning out some pretty clear science here. Let me break this down without the academic jargon: The basic problem: Most studies can't tell the difference between the medicine and why you're taking it. If you're having Tylenol during pregnancy, it's probably because you have a fever, infection, or severe pain. Guess what also increases autism risk? Fever, infections, and severe illness. What makes the Swedish study special: They compared siblings in the same family. Same genes, same environment, same parents - but one child was exposed to acetaminophen in the womb and the other wasn't. This controls for all the family-level stuff that usually confuses these studies. The numbers tell the story: - Regular studies: "5% increased autism risk with acetaminophen" (HR 1.05) - Swedish sibling comparison: "Actually, no increased risk" (HR 0.98, could be 7% protective to 4% harmful - basically noise) - Meanwhile, untreated fever: 40% increased risk, multiple fevers: 212% increased risk We have evidence that fever during pregnancy messes with fetal brain development. We have the best study ever done showing acetaminophen doesn't cause autism. So we're going to... stop treating the fever? It's like refusing to use a fire extinguisher because you're worried it might stain your carpet, while your house burns down. The Swedish study should have ended this debate. When the science is done correctly, the acetaminophen "risk" vanishes completely. Sources: - Swedish study: https://jamanetwork.com/journals/jama/fullarticle/2817406 https://jamanetwork.com/journals/jama/fullarticle/2817406 - Fever-autism evidence: https://molecularautism.biomedcentral.com/articles/10.1186/s13229-021-00464-4 https://molecularautism.biomedcentral.com/articles/10.1186/s...
- Ancapistani 1y ago
  > The Swedish study should have ended this debate. I agree with everything you’ve said except this statement. I’m of the opinion that a single study should never end debate. It may inform policy, sure, but no end debate. Certainly not unless and until it has been replicated by others.
  - ben30 1y ago
    Fair point on the "ended debate" phrasing - that was imprecise on my part. What I should have said is "the Swedish study provides the strongest evidence to date and shifts the burden of proof." It's not actually a single study though. The pattern is consistent across study quality levels: Population studies (many): Small associations, but can't control for confounding Negative control studies (several): Associations weaken when using better controls Sibling studies (multiple, including Swedish): Associations disappear entirely Meanwhile, fever studies (dozens): Consistent risk signals across different populations The Swedish study is just the largest and best-designed in a hierarchy of evidence that all points the same direction. When you see this "dose-response by study quality" pattern - where better methodology consistently yields weaker effects - it's usually a strong signal that the original association was artifactual. The Economist piece published yesterday reinforces this. They mention the NIH study of 200,000 children that "found no link at all" - that's another high-quality study reaching the same conclusion. Meanwhile, the studies showing associations (Nurses' Health Study II, Boston Birth Cohort) are exactly the type of population studies that can't control for the fever/infection confounding. Science is never "settled" in an absolute sense, but the weight of evidence here is pretty clear. We're not waiting for more acetaminophen studies - we're ignoring the ones we already have while making policy based on weaker evidence. That's the real problem with the current policy shift.
bvoq 1y ago
Reasoning from first-principles: Autism is a neurological disorder where you have more island neurons than long reaching connected neurons. Vaccines can't cross the blood brain barrier, thereby they can't cause autism. Simply ruled out. Acetaminophen on the other hand is a drug that numbs the brain. It can at least feasibly have an influence. Next, let's think about painkillers. They numb pain. Pain is linked to far reaching memories and connections. Again, plausible. Sometimes a crazy man says something true.

6 points by uws 1y ago

'Evidence That Acetaminophen Triggers Autism in Susceptible Individuals Has Been Ignored and Mishandled for More Than a Decade' https://www.preprints.org/frontend/manuscript/a6a26b165faf5e655587c37348d84f11/download_pub https://www.preprints.org/frontend/manuscript/a6a26b165faf5e... 'Overwhelming evidence shows that exposure of susceptible babies and children to acetaminophen (paracetamol) triggers many if not most cases of autism spectrum disorder, and that oxidative stress causes susceptibility. However, these conclusions have not yet been widely acknowledged or integrated into clinical practice or regulatory guidelines'

IAmBroom 1y ago
"Not peer-reviewed version" I too can self-publish anything I want. Would you like to know more about how my kool-aid recipe blocks lizard people brain control?

eterm 1y ago

In the words of the UK health secretary: > don’t pay any attention whatsoever to what Donald Trump says about medicine Source: https://www.theguardian.com/politics/2025/sep/23/wes-streeting-rejects-trump-claim-linking-paracetamol-and-autism https://www.theguardian.com/politics/2025/sep/23/wes-streeti...

potatototoo99 1y ago

Unfortunately, with Trump politicizing this so much, the waters are very muddy now on any research on this coming from the US. I'll wait for the EU/Japan researchers' review.

maxerickson 1y ago
How does Trump saying something muddy what scientists and doctors are saying? Even if he wasn't self serving and incurious, his statements wouldn't be worth more than the actual science.
- potatototoo99 1y ago
  If your question is in good faith, US researchers work on US universities and research institutes, both partly sponsored by the US government, who is very vocal on what it thinks the scientific opinion should be. And this new study is a meta study only (at best), very subject to interpretation by what I skimmed.
  - maxerickson 1y ago
    The president is an idiot and RFK is a grifter crank, I don't have to take them seriously just because they have power. Also, it's against the guidelines to say things like "If your question is in good faith".
    - IAmBroom 1y ago
      OK, but the response still answered your question: Trump and his cronies get to pick and choose which research gets funded and publicized through government channels.

ben30 1y ago

The political circus is drowning out some pretty clear science here. Let me break this down without the academic jargon: The basic problem: Most studies can't tell the difference between the medicine and why you're taking it. If you're having Tylenol during pregnancy, it's probably because you have a fever, infection, or severe pain. Guess what also increases autism risk? Fever, infections, and severe illness. What makes the Swedish study special: They compared siblings in the same family. Same genes, same environment, same parents - but one child was exposed to acetaminophen in the womb and the other wasn't. This controls for all the family-level stuff that usually confuses these studies. The numbers tell the story: - Regular studies: "5% increased autism risk with acetaminophen" (HR 1.05) - Swedish sibling comparison: "Actually, no increased risk" (HR 0.98, could be 7% protective to 4% harmful - basically noise) - Meanwhile, untreated fever: 40% increased risk, multiple fevers: 212% increased risk We have evidence that fever during pregnancy messes with fetal brain development. We have the best study ever done showing acetaminophen doesn't cause autism. So we're going to... stop treating the fever? It's like refusing to use a fire extinguisher because you're worried it might stain your carpet, while your house burns down. The Swedish study should have ended this debate. When the science is done correctly, the acetaminophen "risk" vanishes completely. Sources: - Swedish study: https://jamanetwork.com/journals/jama/fullarticle/2817406 https://jamanetwork.com/journals/jama/fullarticle/2817406 - Fever-autism evidence: https://molecularautism.biomedcentral.com/articles/10.1186/s13229-021-00464-4 https://molecularautism.biomedcentral.com/articles/10.1186/s...

Ancapistani 1y ago
> The Swedish study should have ended this debate. I agree with everything you’ve said except this statement. I’m of the opinion that a single study should never end debate. It may inform policy, sure, but no end debate. Certainly not unless and until it has been replicated by others.
- ben30 1y ago
  Fair point on the "ended debate" phrasing - that was imprecise on my part. What I should have said is "the Swedish study provides the strongest evidence to date and shifts the burden of proof." It's not actually a single study though. The pattern is consistent across study quality levels: Population studies (many): Small associations, but can't control for confounding Negative control studies (several): Associations weaken when using better controls Sibling studies (multiple, including Swedish): Associations disappear entirely Meanwhile, fever studies (dozens): Consistent risk signals across different populations The Swedish study is just the largest and best-designed in a hierarchy of evidence that all points the same direction. When you see this "dose-response by study quality" pattern - where better methodology consistently yields weaker effects - it's usually a strong signal that the original association was artifactual. The Economist piece published yesterday reinforces this. They mention the NIH study of 200,000 children that "found no link at all" - that's another high-quality study reaching the same conclusion. Meanwhile, the studies showing associations (Nurses' Health Study II, Boston Birth Cohort) are exactly the type of population studies that can't control for the fever/infection confounding. Science is never "settled" in an absolute sense, but the weight of evidence here is pretty clear. We're not waiting for more acetaminophen studies - we're ignoring the ones we already have while making policy based on weaker evidence. That's the real problem with the current policy shift.

bvoq 1y ago

Reasoning from first-principles: Autism is a neurological disorder where you have more island neurons than long reaching connected neurons. Vaccines can't cross the blood brain barrier, thereby they can't cause autism. Simply ruled out. Acetaminophen on the other hand is a drug that numbs the brain. It can at least feasibly have an influence. Next, let's think about painkillers. They numb pain. Pain is linked to far reaching memories and connections. Again, plausible. Sometimes a crazy man says something true.