No link between autism and paracetamol use during pregnancy, WHO clarifies

• The World Health Organisation (WHO) said there is no conclusive scientific evidence confirming a possible link between autism and use of acetaminophen (also known as paracetamol) during pregnancy. 

• US President Donald Trump had linked autism to childhood vaccine use and the taking of popular pain medication Tylenol by women when pregnant, elevating claims not backed by scientific evidence to the forefront of US health policy. 

• European Union and British health agencies confirmed the safety of paracetamol during pregnancy, disputing a warning from Trump.

What caused this dispute?

• On September 22, the US Food and Drug Administration (FDA) initiated the process for a label change for acetaminophen (Tylenol and similar products) to reflect evidence suggesting that the use of acetaminophen by pregnant women may be associated with an increased risk of neurological conditions such as autism and ADHD in children. 

• The agency also issued a related letter alerting physicians nationwide.  

• According to the FDA, evidence in recent years has suggested a correlation between acetaminophen use during pregnancy and subsequent diagnosis of conditions like autism and ADHD. Multiple large-scale cohort studies, including the Nurses’ Health Study II and the Boston Birth Cohort, found this association. Some studies described that the risk may be most pronounced when acetaminophen is taken chronically throughout pregnancy.  

• However, FDA noted that while an association between acetaminophen and neurological conditions has been described in many studies, a causal relationship has not been established and there are contrary studies in the scientific literature.

• US President Trump delivered medical advice to pregnant women and parents of young children, repeatedly telling them not to use or administer Tylenol and suggesting that common vaccines not be taken together or so early in a child’s life.

WHO issues clarification

• Globally, nearly 62 million people (one in 127) have autism spectrum  disorder, a diverse group of conditions related to development of the brain. 

• Although awareness and diagnosis have improved in recent years, the exact causes of autism have not been established, and it is understood there are multiple factors that can be involved.  

• Extensive research has been undertaken over the past decade, including large-scale studies, looking into links between acetaminophen use during pregnancy and autism. At this time, no consistent association has been established, WHO said.

• WHO recommends that all women continue to follow advice of their doctors or health workers, who can help assess individual  circumstances and recommend necessary medicines. 

• Any medicine should be used with caution during pregnancy, especially in the first three months, and in line with advice from health professionals. 

• Also, a robust, extensive evidence base exists showing childhood vaccines do not cause autism. Large, high-quality  studies from many countries have all reached the same conclusion.

• The childhood immunisation schedule, carefully guided by WHO, has been adopted by all countries, and has saved at least 154 million lives over the past 50 years. 

• The schedule remains essential for the health and wellbeing of every child and every community. These schedules have continually evolved with science and now safeguard children, adolescents and adults against 30 infectious diseases.  

• When immunisation schedules are delayed or disrupted, or altered without evidence review, there is a sharp increase in the risk of infection not only for the child, but also for the wider community.