Is Paracetamol in Pregnancy Linked to Autism or ADHD? What the Best Evidence Says

Two studies, a huge Swedish family-comparison study from 2024 and a 2025 review of the reviews, explained for parents and families

Large studies of pregnant women who took paracetamol (called acetaminophen in the United States) show a very small link with autism and ADHD in their children, but that link disappears when children are compared with their own brothers and sisters. A 2025 review also found that many earlier summaries of this topic were of low quality. Together, the best evidence suggests that family background, not the medicine, explains the small differences seen in earlier research.

Why this question matters so much to families

Pregnancy brings aches, headaches, infections and fevers, and paracetamol is one of the most commonly used medicines in pregnancy around the world. It is also the medicine doctors have usually recommended for pain and fever while a baby is growing.[1] So when headlines suggested it might affect a child's brain, many parents were understandably frightened. Parents of children with autism or ADHD sometimes wondered whether something they did was to blame. This article walks through what two important studies found, in plain language, and what that means for you and your baby. Nothing here replaces advice from your own doctor or midwife.

How the worry began, and why it was hard to settle

For a long time, paracetamol was seen as the safest choice for pain and fever in pregnancy, partly because the other common pain relievers, called non-steroidal anti-inflammatory drugs, are known to affect the baby's circulation and the amount of fluid around the baby.[1] Then researchers began following groups of mothers and their children over many years. Several of these studies found that children whose mothers had taken paracetamol were slightly more likely to be diagnosed later with attention-deficit/hyperactivity disorder (ADHD), and to a lesser extent with autism.[2][3] In 2021 a group of scientists and doctors suggested that pregnant people avoid paracetamol unless they really needed it, although health authorities continued to consider it acceptable.[4]

The trouble was that these studies could not tell the medicine apart from the reasons someone takes it. A woman who takes paracetamol may have a fever, an infection, migraines or long-term pain, and any of these could be linked to how a child develops.[5] Also, autism and ADHD tend to run in families,[6] and mothers who took paracetamol were more likely to have other health conditions.[7] That makes it like noticing that people who carry umbrellas are more likely to get wet: the umbrella is not causing the rain. Scientists call this mix-up confounding. Earlier work from Norway used one clever way around it, comparing siblings, and its early hints suggested that the link became weaker.[8][9] In September 2025, public statements from US officials advising against paracetamol in pregnancy caused fresh alarm, while health agencies in the United Kingdom, Europe and Australia said its use in pregnancy remained safe.[1]

The first study: comparing brothers and sisters in Sweden

Researchers in Sweden used national health records to study 2,480,797 children born between 1995 and 2019, followed until the end of 2021.[4] About 186,000 of these children, roughly 7 in every 100, had mothers who reported using paracetamol during pregnancy, based on a nurse-midwife interview at the first antenatal visit and on prescription records.

The team first compared exposed and unexposed children in the usual way, taking many other factors into account. They saw tiny differences: the chance of an autism diagnosis was about 5% higher and of an ADHD diagnosis about 7% higher in the exposed group. In real numbers, that meant about 1 extra child in 1,000 with autism and about 2 extra children in 1,000 with ADHD by the age of 10.

Then came the key test. They compared children with their own full brothers and sisters, where the mother took paracetamol in one pregnancy but not the other. Because siblings share the same mother, much of the same genetic background and much of the same home environment, this comparison cancels out many hidden family differences. In this comparison, the differences vanished. The results for autism (0.98), ADHD (0.98) and intellectual disability (1.01) were all essentially equal to 1.00, which means no difference at all. Even mothers who took the highest doses showed no pattern of higher risk.

The second study: checking how reliable the summaries were

An international team of researchers then did something different. Rather than collecting new families, they looked at the reviews, the studies that summarise many other studies, on paracetamol and these conditions. They found nine reviews covering 40 individual studies.[1] They rated each review with a standard quality checklist. Seven were judged to be of "critically low" confidence and two of "low" confidence, often because the reviewers had not registered their plan in advance, had not searched thoroughly or had not checked whether the studies themselves could be biased. The reviews also counted many of the same studies again and again, so the pile of evidence looked bigger than it really was.

The review team also looked at the few studies that compared siblings. In each of them, a small link seen in the general comparison faded to nothing among siblings. One of these was the Swedish study above, and another was from Norway.[9] A study from Japan, published after the review's search closed, showed the same pattern for both ADHD and autism.[10] The review's authors concluded that the evidence does not show a clear link between paracetamol in pregnancy and autism or ADHD, and that family factors likely explain the small link seen in older studies.

This kind of study is called an umbrella review, because it gathers many reviews under one roof. Its value is not that it adds new families to the count, but that it tells us how much weight each earlier summary deserves. In this case, the answer was: less than many people had assumed. The review's authors also stressed that the announcements of the previous months had made an accurate reading of the evidence more urgent, since worried mothers and mothers of children with autism deserved information they could trust.[1]

The two studies were published about 19 months apart, and the second one took the first into account. They agree with each other.

Questions parents often ask

Does "no link" mean paracetamol is perfectly safe? Not exactly. Science rarely proves that something has no effect at all; it shows how big any effect could plausibly be. In the Swedish study, the sibling comparison ruled out anything but a very small effect for ordinary use, although the estimates for very heavy use were less precise.[4]

Why did earlier studies say something different? They compared different families with each other, and families differ in ways no questionnaire can capture. The sibling approach is not perfect either, but it is a fairer comparison because the children share so much.

Should I change what I do now? That is a conversation to have with your own doctor or midwife. What the evidence does not support is the idea that paracetamol, taken when it is genuinely needed, is a likely cause of autism or ADHD.[1]

What this means for you and your baby

If you are pregnant, or have had a baby, and you took paracetamol, the best evidence available does not show that it caused autism or ADHD. Autism and ADHD are conditions that arise from many influences, and the largest and best-designed study found no sign that paracetamol was one of them. If your child has been diagnosed with one of these conditions and you took paracetamol, you should not blame yourself.

If you are pregnant and have a fever or pain, the authors of the review advise that untreated high fever is itself harmful to a pregnancy, and that other pain relievers carry known risks for the baby, so paracetamol can be used when needed.[1] As with any medicine, it makes sense to use it only when you need it and to speak with your midwife or doctor if you find you need it often or for a long time. Never stop or start a medicine because of a headline without talking to your care team.

It is fair to say what these studies cannot tell us. They cannot prove that no harm is possible in every situation, and researchers are still studying whether very frequent or long-term use, or use at certain stages of pregnancy, may matter.[4] The Swedish records did not capture every over-the-counter tablet, and only some of the diagnoses had been checked for accuracy. But together, the evidence points in a reassuring direction.

What researchers are working on next

Scientists want to study more sibling groups from other countries, and to look more closely at how much paracetamol was taken, for how long and at what point in pregnancy. They also want to understand better the difference between the effect of a fever or an infection and the effect of the medicine used to treat it, and to look at more aspects of child development beyond autism and ADHD.[1] Future reviews should be planned in advance and checked for bias so that families and doctors can trust them.

A closing thought for parents

Uncertainty is uncomfortable, especially in pregnancy, when every decision feels important. It may help to know that the size of the effect people were worried about was very small to begin with, that it disappeared once families were compared fairly, and that the reviews sounding alarms were weaker than they looked. If you are worried, bring your questions to your doctor or midwife. They can help you weigh the risks of untreated pain or fever against the reassuring research described here.

References

  1. Sheikh J, Allotey J, Sobhy S, Plana MN, Martinez-Barros H, Naidu H, Junaid F, Sofat R, Mol BW, Kenny LC, Gladstone M, Teede H, Zamora J, Thangaratinam S. Maternal paracetamol (acetaminophen) use during pregnancy and risk of autism spectrum disorder and attention deficit/hyperactivity disorder in offspring: umbrella review of systematic reviews. BMJ. 2025;391:e088141. doi:10.1136/bmj-2025-088141 ↩
  2. Gou X, et al. Association of maternal prenatal acetaminophen use with the risk of attention deficit/hyperactivity disorder in offspring. Aust N Z J Psychiatry. 2019;53:195-206. doi:10.1177/0004867418823276 ↩
  3. Masarwa R, et al. Prenatal exposure to acetaminophen and risk for attention deficit hyperactivity disorder and autistic spectrum disorder. Am J Epidemiol. 2018;187:1817-1827. doi:10.1093/aje/kwy086 ↩
  4. Ahlqvist VH, Sjöqvist H, Dalman C, Karlsson H, Stephansson O, Johansson S, Magnusson C, Gardner RM, Lee BK. Acetaminophen use during pregnancy and children's risk of autism, ADHD, and intellectual disability. JAMA. 2024;331(14):1205-1214. doi:10.1001/jama.2024.3172 ↩
  5. Dreier JW, et al. Fever in pregnancy and health impacts in the offspring. Pediatrics. 2014;133:e674-e688. doi:10.1542/peds.2013-3205 ↩
  6. Faraone SV, Larsson H. Genetics of attention deficit hyperactivity disorder. Mol Psychiatry. 2019;24:562-575. doi:10.1038/s41380-018-0070-0 ↩
  7. Bandoli G, et al. Acetaminophen use in pregnancy: examining prevalence, timing, and indication of use. Paediatr Perinat Epidemiol. 2020;34:237-246. doi:10.1111/ppe.12595 ↩
  8. Brandlistuen RE, et al. Prenatal paracetamol exposure and child neurodevelopment: a sibling-controlled cohort study. Int J Epidemiol. 2013;42:1702-1713. doi:10.1093/ije/dyt183 ↩
  9. Gustavson K, et al. Acetaminophen use during pregnancy and offspring attention deficit hyperactivity disorder - a longitudinal sibling control study. JCPP Adv. 2021;1:e12020. doi:10.1002/jcv2.12020 ↩
  10. Okubo Y, et al. Maternal acetaminophen use and offspring's neurodevelopmental outcome: a nationwide birth cohort study. Paediatr Perinat Epidemiol. 2025;ppe.70071 (published online). doi:10.1111/ppe.70071 ↩