A mother's diet, medication, and lifestyle choices during pregnancy play a crucial role in her child's long-term health and development, making it essential to use medications with caution during this stage. Now, adding to growing concerns, a small study suggests that a commonly used painkiller may increase the risk of Attention-Deficit/Hyperactivity Disorder (ADHD) in children.

ADHD is a developmental disorder that affects a person's ability to focus, control impulses, and regulate energy levels. It is commonly diagnosed in childhood but can persist into adulthood.

Can acetaminophen, a painkiller also sold as paracetamol, contribute to ADHD? Research on this question has yielded mixed results. While a study published in 2019 showed that it could elevate the risk by 20%, another study last year that followed up around 2.5 million kids found no significant link.

Since many studies depend on self-reported data on acetaminophen use, the results could be inaccurate. To get a clearer picture, researchers in a recent study analyzed blood samples from 307 pregnant women to detect actual markers of the drug and assess its potential impact on their children's neurodevelopment.

The results showed that children whose mothers had acetaminophen in their blood during the second trimester were over three times more likely to be diagnosed with ADHD.

The researchers explained that it is because acetaminophen use during pregnancy affected how certain genes function in the placenta, in turn influencing the development of babies. While prenatal exposure to the drug raised immune system activity in girls, it reduced cell energy production in both boys and girls. It was also linked to increased expression of the immune-related gene IGHG1, which was associated with a 5.22% higher likelihood of ADHD in girls.

However, the findings may not be generalized as the study is based on a small sample size and all participants were Black and lived in the same city. Also, the study only measured blood markers of paracetamol at a single point in time and did not check the effects of the dosage of the medicine.

"[Paracetamol] is currently the first-line therapeutic option for pain and fever in pregnancy. But I think agencies like the [US Food and Drug Administration] and different obstetric and gynecology associations need to be continually reviewing all available research and updating their guidance," said lead researcher Brennan Baker at the University of Washington in Seattle.

He also cautioned that many people take the medication without knowing that it contains acetaminophen, as it may be an active ingredient in some cold medications.

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