New Delhi : While paracetamol or acetaminophen has long remained the first choice of painkiller in pregnancy, a new study claims it may lead to neurodevelopmental disorders (NDDs), such as autism and attention-deficit/hyperactivity disorder (ADHD) in babies.

Acetaminophen is the most commonly used over-the-counter medication taken during pregnancy, with more than 50 per cent of pregnant women using the drug worldwide. It is widely used for headaches, pain, or fever by pregnant women.

Researchers from the universities of Massachusetts and Harvard analysed 46 studies that incorporated data from more than 100,000 people. Of these, 27 studies reported significant links to NDDs.

“The majority of the studies reported positive associations of prenatal acetaminophen use with ADHD, ASD, or NDDs in offspring,” said corresponding author Andrea A. Baccarelli from the Harvard T.H. Chan School of Public Health.

Acetaminophen is known to cross the placental barrier and may trigger oxidative stress, disrupt hormones, and cause epigenetic changes that interfere with foetal brain development, which may explain the links, the researcher said.

Prior literature has also shared the potential link between acetaminophen and neurodevelopmental disorders.

A 2017 study indicated a higher risk for ADHD among mothers who used acetaminophen for 22 to 28 days. Another study published in February also suggested that acetaminophen exposure increased the odds for ADHD — although only in girls.

The study noted that although acetaminophen remains the preferred painkiller due to its relatively favorable safety profile compared to other medications, its use should be approached judiciously, particularly in light of potential implications for foetal development during the perinatal period.

“Appropriate and immediate steps should be taken to advise pregnant women to limit acetaminophen consumption to protect their offspring’s neurodevelopment,” Baccarelli said, while also urging the need for more studies to ascertain the risk.