Paracetamol Use By Pregnant Mothers Can Lead to ADHD, Autism In Children; New Evidence Suggests Strong Link [Study]

Acetaminophen, commonly known as Paracetamol, is perhaps that one medication that finds a place in nearly all the medicine cabinets across the world. It is safe and inexpensive, and mostly sold as an over-the-counter drug. However, according to a new study, the use of the universal antipyretic/analgesic by pregnant women may result in neurobehavioral disorders in their children.

Led by researchers from Barcelona Institute for Global Health (ISGlobal), the epidemiological study analyzed over 70,000 children in six cohorts across multiple European countries (Denmark, Greece, Italy, Netherlands, Spain, and United Kingdom). A notable link between the use of acetaminophen during pregnancy and symptoms of attention-deficit/hyperactivity disorder (ADHD) and autism spectrum conditions (ASC) in children was found.

"These results replicate previous work and support providing clear information to pregnant women and their partners about potential long-term risks of acetaminophen use," wrote the authors in the study that was published in the journal European Journal of Epidemiology.

Paracetamol and Neurobehavioral Disorders

ADHD is a disorder that results in above-normal levels of impulsive and hyperactive behaviors. Individuals with ADHD may additionally have trouble with focusing their attention on a specific task or even sit still for long durations. While it begins in childhood, it can continue into adulthood as well. ASC is a lifelong developmental condition that affects communication and interactions with others. Individuals with ASC may find sensory inputs such as loud noises or bright lights overwhelming. Also, unfamiliar situations and places can make them upset or anxious.

Acetaminophen is considered to be the safest antipyretic/ analgesic for use by pregnant women and children. Approximately, 46 percent to 56 percent of pregnant in developed countries are found to use paracetamol at some point during the course of pregnancy. Nevertheless, an increasing amount of evidence has found an association between prenatal paracetamol exposure and poorer cognitive performance. The data have also liked prenatal paracetamol exposure to additional behavioral problems, and ADHD and ASC symptoms.

However, these older studies have attracted criticism on account of the heterogeneity of their evaluation criteria. Therefore, in the new study, "an effort was made to harmonise the assessment of ADHD and ASC symptoms and the definition of paracetamol exposure," illustrated Sílvia Alemany, lead author of the study, in a statement. She added that uniform criteria were applied to all the cohorts in order to reduce the heterogeneity that has served as the weakness of previous studies.

The cohorts in the study were: Avon Longitudinal Study of Parents and Children (ALSPAC); Danish National Birth Cohort (DNBC); Gene and Environment: Prospective Study on Infancy in Italy (GASPII); Generation R Study; INMA (including four sub-cohorts); and Mother-Child Cohort in Crete (RHEA).

Exposure and Increased Risk

For the study, the scientists analyzed 73,881 children in six cohorts, and the available data on their exposure to paracetamol was examined. Maternal questionnaires or interviews were utilized to analyze prenatal and postnatal (up to 18 months) exposure. Symptoms of ASC and ADHD symptoms were evaluated at 4–12 years of age employing accepted instruments or methods. Finally, the children were classified as having borderline or clinical symptoms using recommended cutoffs for every instrument.

Based on the cohort, 14 to 56 percent of the mothers reported consuming paracetamol during pregnancy. It was found that children who were exposed to the drug before birth had an increased likeliness of 19 percent of developing ASC symptoms, while 21 percent were more likely to develop symptoms of ADHD than children who had no exposure to paracetamol. 

The proportion of children having clinical or borderline symptoms ranged between 1.2 percent and 12.2 percent for ADHD, and between 0.9 percent and 12.9 percent for ASC. "Our findings are consistent with previous research. We also found that prenatal exposure to paracetamol affects boys and girls in a similar way, as we observed practically no differences," remarked Alemany. 

No Use, No Link

In addition to prenatal exposure, the team also investigated postnatal exposure to paracetamol, and observed no link between the use of the drug during childhood and symptoms of ASC and ADHD. The heterogeneity of postnatal paracetamol exposure among the different cohorts ranged from 6 percent to 92.8 percent. Therefore, the authors stressed the need for further studies.

Jordi Sunyer, last author of the study, however, noted that the results of the current research addressed some of the drawbacks of previous meta-analyses."Considering all the evidence on the use of paracetamol and neurological development, we agree with previous recommendations indicating that while paracetamol should not be suppressed in pregnant women or children, it should be used only when necessary," concluded Sunyer.