A study led by Professor Ian Chi Kei Wong from the School of Pharmacy, Faculty of Medicine at The Macau University of Science and Technology (MUST) provides important new evidence regarding the safety of paracetamol (acetaminophen) use during pregnancy. The study, entitled “Prenatal Acetaminophen (Paracetamol) Use and the Risk of Autism and/or Attention-Deficit/Hyperactivity Disorder Among Sibling-Matched Cohorts”, was published online on 29 June 2026 in JAMA Internal Medicine.
Professor Ian Chi Kei Wong is Distinguished Professor of the School of Pharmacy, Faculty of Medicine
Paracetamol is the most commonly used medication for pain and fever during pregnancy and is widely recommended as a first-line treatment by healthcare authorities worldwide. However, concerns have emerged in recent years regarding a possible association between prenatal paracetamol exposure and neurodevelopmental disorders, particularly autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD). These concerns have attracted considerable public attention and generated anxiety among expectant mothers and healthcare professionals.
Professor Wong’s study used a rigorous sibling-matched design, which compared siblings from the same mother, with at least one sibling exposed to paracetamol during pregnancy and the other unexposed. This study design overcomes the main criticism of previous studies that reported links between prenatal paracetamol exposure and ASD or ADHD – namely, that mothers who take paracetamol during pregnancy may inherently different from those that do not. The findings clearly show no association between paracetamol use and the development of ASD and ADHD, which provide timely reassurance for expectant mothers and clinicians worldwide.
Dean of the Faculty of Medicine, Professor Manson Fok, congratulated Professor Wong and the international research team on this achievement. He noted that the publication of such a high-impact study in one of the world's leading medical journals reflects the Faculty’s commitment to advancing evidence-based medicine and addressing questions of major public health importance through rigorous scientific research.
Professor Wong, who is also Regius Professor at Aston University, UK added. “Questions surrounding medication use during pregnancy can generate significant anxiety for expectant mothers and families. Through the support of the Laboratory of Data Discovery for Health (D24H) at AIR@InnoHK, the Research Grants Council, and the Hospital Authority, we were able to leverage population-scale health data to address this important public health question with an unprecedented level of rigor.”
The article, “Prenatal Acetaminophen (Paracetamol) Use and the Risk of Autism and/or Attention-Deficit/Hyperactivity Disorder Among Sibling-Matched Cohorts” can be accessed using this link.
