Long-term use of paracetamol during pregnancy is associated with the risk of neurodevelopmental disorders like attention deficit hyperactivity disorder (ADHD) and autistic spectrum disorder (ASD), a study has found.

Previous studies showed that long-term administration of low doses of paracetamol also known as acetaminophen may affect the development of the fetal nervous system. This effect is often seen years after exposure during childhood. The new study, appearing in the American Journal of Epidemiology, showed that prolonged exposure to acetaminophen found in the commonly used drug for the treatment of pain and fever, during pregnancy is associated with a 30 per cent increase in relative risk for ADHD.

While there is also a 20 per cent increase in relative risk for ASD, compared to those who did not take the medications. "The findings suggest an association between prolonged acetaminophen use and an increase in the risk of autism and ADHD," said Ilan Matok, from the Hebrew University of Jerusalem in Israel. For the new research, the team conducted a systematic review and meta-analysis 1,32,738 mother and child pairs with a follow-up period of three to 11 years.

The researchers believe that it is important to understand that pain and fever during pregnancy can have a detrimental effect on the developing foetus, but acetaminophen is still considered a safe drug for use during pregnancy. Therefore, if a pregnant woman has fever and/or pain, acetaminophen can be taken for a short period, and if the fever or pain continues beyond that, she should consult her physician regarding further treatment. "While the unnecessary use of any medication should be avoided in pregnancy, we believe our findings should not alter current practice and women should not avoid the use of short-term acetaminophen when clinically needed," Matok said.