From Conception to Early Childhood: Managing pain, fever, and neurodevelopmental risk. Time to apply some common sense? Time for NAC?

 

Donald Trump recently reignited debate about Tylenol (paracetamol/acetaminophen) in pregnancy. His comments drew attention to research linking prenatal use to higher rates of autism and ADHD.

A large review of 46 studies, including work from Harvard, found consistent associations between paracetamol in pregnancy and neurodevelopmental risks. The FDA now advises caution: use the lowest dose for the shortest time.

 

Tylenol in pregnancy linked to higher autism risk, Harvard scientists report

Researchers reviewing 46 studies found evidence linking prenatal acetaminophen (Tylenol) exposure with higher risks of autism and ADHD. The FDA has since urged caution, echoing scientists’ advice that the drug be used only at the lowest effective dose and shortest duration. While important for managing fever and pain in pregnancy, prolonged use may pose risks to fetal development. Experts stress careful medical oversight and further investigation.

 Why the concern?

• Paracetamol depletes glutathione (GSH), the body’s main antioxidant.
• This raises oxidative stress in both mother and fetus.
• The fetus has weak antioxidant defences, so damage may occur during critical brain development.

But here is the dilemma: the fever, pain, or inflammation that drives a mother to take paracetamol is itself risky. We have long known from maternal immune activation models that fever and cytokine surges in pregnancy can disturb fetal brain development and cause autism or schizophrenia. There is also evidence linking maternal immune activation to ADHD in the offspring.

So, what is the solution? Pair paracetamol with NAC.

Why NAC?

• NAC (N-acetylcysteine) is a precursor to glutathione.
• It’s used worldwide in emergency rooms to save lives after paracetamol/ acetaminophen overdose.
• In pregnancy, NAC has been shown to reduce miscarriage risk by 50%,

N-acetyl cysteine for treatment of recurrent unexplained pregnancy loss

• Increased pregnancy continuation: Women receiving NAC and folic acid were 2.9 times more likely to continue their pregnancies beyond 20 weeks compared to those receiving folic acid alone
• Higher take-home baby rate: The NAC group had a 1.98 times higher rate of delivering a live baby.
• These findings suggest that NAC, an antioxidant, may help mitigate oxidative stress, a factor implicated in pregnancy loss.

  

A combined Paracetamol/acetaminophen + NAC pill would:

• Prevent liver toxicity,
• Buffer oxidative stress in the fetus,
• Eliminate the overdose suicide risk that haunts current paracetamol use.

So far, no company has produced it. Perhaps the “rotten egg” smell of NAC is a barrier—but solid sustained-release tablets avoid this.

 

Why Paracetamol/acetaminophen use is problematic in under 5s

Paracetamol depletes glutathione (GSH), the body’s primary antioxidant, increasing oxidative stress. A fetus with some genetic predispositions might already be in a state of oxidative stress, as might the mother

Paracetamol is mainly metabolized in the liver. A small fraction is metabolized into NAPQI — a reactive toxic metabolite. Glutathione (GSH) neutralizes NAPQI by forming a harmless conjugate.

If GSH stores are low (or paracetamol is taken in high doses), NAPQI accumulates, causing liver toxicity and GSH is exhausted raising oxidative stress.

Acute oxidative stress can be very damaging to developing brains. The risk after 5 years old fades away, other than in those who have already exhibited a profound metabolic/mitochondrial condition.

Why Oxidative Stress Rises in Pregnancy

Placental development: Early pregnancy is low-oxygen; as blood flow increases, oxygen surges and generates reactive oxygen species (ROS).

High metabolic demand: The mother and placenta require much more energy, leading to increased mitochondrial ROS.

Immune adaptations: Pregnancy involves a shift in maternal immunity, with inflammatory cytokines contributing to oxidative stress.

Fetal growth: Rapid cell division and organ development naturally produce oxidative byproducts, while the fetus’s antioxidant defenses are immature.

Limited antioxidant reserves: Maternal antioxidants (glutathione, vitamins C & E, enzymes) are partly depleted as pregnancy progresses.

 

Compounding Risk Factors

Polycystic Ovary Syndrome (PCOS): Associated with high androgens, insulin resistance, and chronic inflammation. These increase oxidative stress and are linked to higher autism risk in offspring.

Gestational Diabetes: Maternal hyperglycemia and insulin resistance increase ROS, damage the placenta, and expose the fetus to oxidative and metabolic stress.

Other amplifiers: Obesity, infection, fever, or poor nutrition further elevate oxidative stress.

 

How Oxidative Stress Affects the Fetus

Neurodevelopmental disruption: ROS can damage neural stem cells, impair migration, and disturb synapse formation.

Epigenetic reprogramming: Oxidative stress alters DNA methylation and gene expression, shaping long-term brain function.

Immune activation: Inflammatory cytokines cross the placenta and disturb fetal brain development.

Mitochondrial dysfunction: ROS damage fetal mitochondria, reducing energy for developing neurons.

Neurotransmitter imbalance: Antioxidant depletion disrupts glutamate/GABA balance and monoamine systems.

 

Consequences for the Unborn Child

Most pregnancies manage oxidative stress without harm, thanks to maternal–fetal antioxidant defences.

When oxidative stress overwhelms these defences—especially in mothers with PCOS, GDM, or infections—the risk of complications rises:

Preterm birth, growth restriction, or preeclampsia

Higher vulnerability to neurodevelopmental disorders, including autism spectrum disorder (ASD) and ADHD.

Genetic predispositions in antioxidant or mitochondrial pathways may make some fetuses especially sensitive to these oxidative challenges.

Pregnancy naturally involves a controlled increase in oxidative stress, but when combined with maternal conditions like PCOS, gestational diabetes, or acute infections, the oxidative burden can exceed protective capacity. This imbalance may impair placental function and fetal brain development, increasing the risk of adverse outcomes, including autism. 

 

Pregnancy: Choosing safer options for pain and fever

• Paracetamol → Remains the best option if pain relief is absolutely needed, but should be paired with NAC.
• NSAIDs (ibuprofen, mefenamic acid) → Unsafe in later pregnancy due to fetal kidney damage and premature closure of the ductus arteriosus. Premature closure of the ductus arteriosus is a serious condition that occurs when the fetal blood vessel connecting the pulmonary artery to the aorta closes before birth. Do not use NSAIDs!
• NAC supplementation → Low-cost, safe, and evidence-backed for reducing oxidative stress.

 

Infancy and Early Childhood

• Paracetamol
• Licensed from birth.
• Effective for pain and fever, but still depletes glutathione.
• In at-risk infants (metabolic or mitochondrial issues), consider pairing with NAC.
• NSAIDs (ibuprofen, Ponstan)
• Suitable from 3–6 months (depending on guidelines).
• Do not deplete glutathione, making them safer for oxidative stress.
• Hydration matters to protect kidneys.

 

Vaccinations, Fever, and Oxidative Stress

Vaccines work by briefly activating the immune system. This triggers a short burst of oxidative stress—far smaller than that caused by actual infections.

• Healthy children clear this easily.
• At-risk children (mitochondrial disease, metabolic errors, weak antioxidant systems) may struggle, leading to fatigue, regression-like symptoms, or metabolic instability.

Medication choices around vaccines

• NSAIDs → Good for post-vaccine fever. Avoid routine pre-dosing to prevent dampening immunity, unless the child is in the at-risk group.
• Paracetamol → Pre-vaccine dosing can reduce antibody production and reduce GSH. Post vaccine should be paired with NAC.
• Montelukast → Anti-inflammatory, theoretically helpful in at-risk children, but not tested in trials, but is used at metabolic/mitochondrial clinics treating children.
• NAC → Biologically plausible support for antioxidant status, though not studied formally in this setting.

Mainstream pediatrics avoids routine prophylactic anti-inflammatories, but some specialists (e.g., Dr. Kelley, Johns Hopkins) do use them selectively in fragile children. Using paracetamol without NAC is a bad idea.

 

Metabolic Decompensation: The Hidden Risk

Some children with mitochondrial or metabolic disorders cannot handle stress from fever or illness. This can trigger:

• Energy failure (low ATP)
• Accumulation of toxic metabolites (lactate, ammonia)
• Seizures or regression

In developing brains, these crises can leave permanent autism-like features and/or intellectual disability. These symptoms are secondary to brain injury. Prevention is key:

• Hydration, glucose support
• Early fever control
• Antioxidant support (NAC, vitamins C & E)

 

Key Takeaways

• Pregnancy: If pain relief is needed, paracetamol + NAC is safer than paracetamol alone. Avoid NSAIDs.
• Infancy: Paracetamol is widely used, but NSAIDs are safer from 3 months onward when oxidative stress is a concern.
• Vaccination: Vaccines prevent far greater oxidative stress from infections. At-risk children may benefit from antioxidant or anti-inflammatory support, but this should be individualized.
• Metabolic decompensation: Recognize and prevent crises in vulnerable children—this reduces risk of secondary neurodevelopmental injury.

 

Conclusion

Paracetamol has been trusted for decades, but its link with oxidative stress and neurodevelopmental risk is becoming harder to ignore. A Paracetamol + NAC pill makes both medical and common sense—safer for mothers, safer for children, and suicide-proof.

Until then, thoughtful use of NAC, NSAIDs, and tailored fever management could make a real difference in protecting brain development from conception through early childhood.

 

My original draft post was rather long, so here is the “optional” part 2, for any avid readers out there!

 

 

Part 2: Vaccines, Oxidative Stress, and Children at Risk

Why some kids may react differently — and what parents and clinicians can do

Vaccines are one of the greatest public health achievements, protecting children from infections that would otherwise cause significant illness, hospitalization, or death. But for children with mitochondrial disorders, metabolic diseases, or weak antioxidant systems, even routine vaccination can temporarily stress the body.

How Vaccines Trigger Oxidative Stress

• Vaccination works by activating the immune system, prompting cytokine release, mild inflammation, and reactive oxygen species (ROS) production.
• In healthy children, this burst is short-lived. Antioxidant defences like glutathione, superoxide dismutase, and dietary vitamins C & E neutralize ROS quickly.
• In children with mitochondrial or metabolic vulnerabilities, baseline ROS is already elevated, and antioxidant defences may be limited. A small extra load from vaccination can feel disproportionately stressful.

 

Why Some Children React Differently

Mitochondrial Disorders

• Mitochondria produce ATP and ROS. Dysfunction means higher baseline oxidative stress and lower energy reserves.
• A vaccine-induced oxidative spike can linger longer, leading to fatigue, metabolic stress, or regression-like symptoms.

Metabolic Disorders

• Children with amino acid, fatty acid, or urea cycle defects have limited antioxidant capacity.
• ROS accumulation may overwhelm defences, causing secondary mitochondrial stress or toxic metabolite build-up.

Genetic Variants

• Some children carry variants that reduce glutathione production or antioxidant enzyme activity (e.g., GSTM1/GSTT1 deletions, MTHFR variants, impaired SOD/catalase).
• Even minor oxidative challenges can temporarily disturb synapse formation, neurotransmitter balance, and myelination in the developing brain.

 

Medications Around Vaccination

NSAIDs

• Symptom-driven use for fever or pain post-vaccine is generally safe.
• Routine prophylactic use is usually avoided because it can reduce antibody responses, but specialists consider this is likely minimal

Paracetamol

• Pre-vaccine dosing can modestly blunt antibody formation in some vaccines and is unwise because it reduces GSH just before it will be needed most.
• Post-vaccine, symptom-driven use is often considered safe, but is unwise due to the ruction in GSH when needed most
• High-risk children should always avoid paracetamol unless paired with NAC to protect glutathione and limit oxidative stress.

NAC (N-acetylcysteine)

• Biologically plausible support for antioxidant status in at-risk children.
• Safely used during pregnancy and by babies
• Not yet studied in formal vaccine trials, but safe and used in clinical settings for other oxidative stress conditions.

Montelukast

• Anti-inflammatory, may reduce oxidative stress, but not proven for vaccine prophylaxis.
• Used by children at vaccination time when already prescribed it for asthma/allergic disease.

 

Managing Vaccination in At-Risk Children

1.     Ensure good hydration, feeding, and metabolic stability before vaccination.

2.     Monitor closely for post-vaccine fever, fatigue, or regression-like symptoms.

3.     Have supportive measures ready:

o    NAC or other antioxidant support

o    Symptom-driven NSAIDs

o    Avoid paracetamol unless paired with NAC

o    Quick access to a specialist if metabolic stress occurs

 

Takeaways for Parents and Clinicians

• Vaccines do cause a small, transient oxidative stress, but it is far less than the oxidative burden from infections.
• Children with mitochondrial or metabolic vulnerabilities may need extra care before and after vaccination.
• NAC, hydration, symptom-driven NSAIDs, and careful monitoring can reduce risk without compromising immunity.
• Always coordinate with a metabolic or mitochondrial specialist when planning vaccination for high-risk children.

By understanding oxidative stress, supporting antioxidant defences, and tailoring care, parents and clinicians can protect both immunity and neurodevelopment.

Since most parents, in reality, do not have access a mitochondrial specialist it pays to do your homework in advance. All the needed resources are in plain view.

You do wonder why nobody makes a combined Paracetamol/acetaminophen + NAC pill.

Such a pill is perfect for pregnant women.

Nobody would be able to commit suicide with this pill. This pill blocks the harmful effect on the liver that ultimately can lead to death.

NAC does smell of rotten eggs. One argument against such a pill is that it would stink and pregnant women are often feeling nausea. If the pill is solid (like NAC Sustain) there is no smell of rotten eggs. So you certainly can have a combined pill.

Personally, I would ban all liquid formulations of Paracetamol, other than for babies under 3 months. Many countries have long used exclusively Ibuprofen or Ponstan for children. Once a child is 5 years old the potential for paracetamol to do neurodevelopmental harm should have faded.

You can give babies NAC, it is sold in a liquid form for this purpose. NAC acts as a mucolytic, meaning it thins mucus in the airways.

How common is Metabolic Decompensation as a cause of severe autism? We know it exists, but I think we will never know how common it is. Hannah Poling is the best-known example. Evidence of an inconvenient truth.