Tylenol: Does it Cause ADHD and Autism, or Is it Safe During Pregnancy?

Acetaminophen (Tylenol) — most people reach for it for everyday headaches like it's no big deal, and 2/3 of women have used it in pregnancy. Yet acetaminophen is not benign. For example, it is one of the major contributors to liver disease and the most common cause of liver transplantation in the US every year. 

Acetaminophen has long been considered generally safe for use during all stages of pregnancy, making it a first-choice pain and fever medication for pregnant women. Given the large number of pregnant women using the drug, even a small increase in risk of adverse outcomes in offspring can have important implications for public health and outcomes for our next generation. 

Only a few years back, the medical community consensus on Tylenol use during pregnancy was that it should be used with caution after several studies came out suggesting it could be interfering with normal fetal brain and nervous system development, endocrine function, and sexual differentiation – to name a few.

Can an Untreated Fever During Pregnancy Cause Birth Defects?

On the other side of the aisle, there’s also been data to support that untreated maternal fever, especially when high, during pregnancy may be associated with birth defects (animal study only), neurodevelopmental disorders, and maternal health complications – putting soon to be mothers in a tough position given the FDA has recommended all NSAIDs be avoided at 20 weeks of pregnancy and beyond due to its potential to create low amniotic fluid levels and kidney problems in unborn babies. 

This begs the question, what can a pregnant woman use to reduce fever and also address headaches should these arise? 

Can Tylenol Use During Pregnancy Cause ADHD or Autism?

The largest concerns and headlines centered around Tylenol suggested increased risk of ADHD, ADD, and Autism – based on observational, cohort data that supported a potential association (this is not the same as causation). Observational studies look at retrospective (past) data to identify patterns and trends, while cohort studies follow a group of people over time to observe outcomes. There’s even an active class action lawsuit (still going as of June 2024) against Tylenol for its potential link to autism, which has a projected average settlement of up to $500K per person.

The most notable of this research came out in 2021, where a team of 13 scientists cautioned against the use of pain relievers with acetaminophen (also known as paracetamol) by pregnant women, citing a growing body of research that suggests the drug may alter fetal development. 

The consensus statement, published in the journal Nature Reviews Endocrinology, was supported by 91 researchers, clinicians, and public health experts from around the world. They alerted the medical community that acetaminophen may be at least partially responsible for rising rates of male reproductive disorders (like undescended testes, an increased risk factor for infertility), as well as cognitive, learning, and behavioral problems among children (like ADHD, ADD, and ASD) over the past several years. 

Their concluding statement was a recommendation for pregnant women to avoid acetaminophen altogether unless otherwise prescribed it by a medical professional.

Findings from New Research on Acetaminophen Use During Pregnancy

Newer, higher quality data released may help resolve the quandary pregnant women find themselves in when experiencing a headache or fever and wondering whether Tylenol is safe to use. This recent study, published in JAMA on April 9th, 2024, used a sibling analysis across nearly 2.5 million children in Sweden born to singleton pregnancies (that’s one baby to a pregnancy) between 1995 and 2019. This means they compared children born from the same mother, with one being exposed to Tylenol while in the womb and the other not. This data was self reported, meaning mothers were asked several times during pregnancy to report their intake of acetaminophen, which was compared against the child’s medical records later on.

What did they find?

In total, 185 909 children (7.49%) of children had been exposed to acetaminophen in this study. In models without sibling control, similar findings to previous data still ring true: there was a modest increased risk for autism, ADHD, and intellectual disability. However, in models with sibling control, they found no evidence that acetaminophen use during pregnancy was associated with autism,  ADHD or intellectual disability. There was also no evidence of a dose-dependent pattern in models with sibling control, meaning more acetaminophen exposure didn’t increase the risk of diagnosis. 

This doesn't mean that observational study findings aren’t indicative of something greater or worth paying attention to over time as new data can always, again, emerge, but it can be hard to control for confounding variables. In a sibling analysis on the other hand, because the mother remains consistent, you can control for things like genetic factors, early life environment, and socioeconomic status, thereby, reducing potential bias in the results. 

While a sibling analysis is still not the gold standard, double-blind, randomized control trial, it’s still an improvement from previous study designs where associations between Tylenol use during pregnancy and things like ADHD, ADD and autism were found – which were primarily observational or cohort based. 

Is Acetaminophen Use During Pregnancy Now Safe?

Ultimately, the authors of this newer research concluded that the associations observed in the previous study were likely due to familial and environmental confounding factors – and from their analysis, suggested there is no association of acetaminophen use during pregnancy and a child’s risk of developing ASD, ADHD, or another intellectual disability.

That said (and as goes for many conversations around health and wellbeing), there’s often evidence to both sides of the argument – which is relevant here given that leading up to this year, we had decent data to support avoiding Tylenol during pregnancy was a solid course of action. 

The beauty in research is that we’re constantly learning, acquiring new insights, and gathering higher quality data from more thoughtfully run studies. So, while this new sibling analysis suggests using acetaminophens like Tylenol during pregnancy is safe, the choice ultimately comes down to what you’re most comfortable with. 

What's a Mom to Do? Alternatives to Tylenol During Pregnancy 

Headaches and fever can both occur during pregnancy and other commonly used pain medications like ibuprofen are not recommended for use. So what can you do? 

If you’re experiencing a headache, or having a fever and choose to take acetaminophen, statistically speaking you’re in the clear. Tylenol is still considered the safest prenatal option for fever and headache, and today, we have even stronger data to reinforce that. So don’t beat yourself up for taking care of your well-being or making a decision where there are both benefits and potential risks on the line (i.e., unchecked fever).

But as goes with anything, excessive use (i.e. daily or multiple times a week) may be worth reconsidering and replacing with natural approaches to the degree possible, particularly because regular Tylenol use has been associated with other health risks. 

With headaches, particularly if they are recurring, it’s important to address any root causes from inadequate hydration to fatigue to anemia, with your healthcare provider.

Here are also 5 safe, natural tips that you can safely use to help reduce headaches in pregnancy:

1. Apply a few drops of lavender oil or peppermint oil to the temples. These have been shown to safely and effectively reduce headaches and can be used topically in pregnancy.

2. Take 2 ginger capsules if you feel a headache coming on, and repeat again in a few hours. It is a natural anti-inflammatory and pain-relieving herb that’s considered safe in pregnancy in a dose of up to 2 gms per day.

3. If you suffer from migraines, Riboflavin (Vitamin B2) at 400 mg/day has been found effective for prevention, and safe for daily use in pregnancy. You can also do a migraine journal to identify and remove any potential triggers.

4. Many headaches are a result of neck and shoulder tension, so don't overlook the value of addressing posture, sleeping positions, a change of pillows, and massage for headache prevention and relief.

5. Take a warm bath with 1-2 cups of Epsom salts and 5-7 drops of lavender essential oil. The combination of magnesium in the Epsom salts, the aromatherapy from lavender, and hot water is deeply relaxing and lavender aromatherapy may help relieve a headache.

If you have a sudden onset headache, a more severe headache than usual, any visual changes or upper abdominal pain with your headache, or a history of high blood pressure, please see your midwife or physician promptly as these can be signs of more serious illness, like pregnancy induced hypertension or preeclampsia.

If you have frequent headaches, getting to the root cause by making sure you’re getting enough sleep, reducing excessive inflammation with dietary and lifestyle changes, getting all of your essential nutrients, including protein, and looking into environmental allergies or other triggers may be helpful You may also want to consider working with a functional medicine, integrative medicine, or naturopathic physician skilled in pregnancy care.