Acetaminophen is one of the very few painkillers considered generally safe to use during pregnancy. A new study, however, suggests it may not be so safe after all, after identifying a link between prenatal exposure to the drug and symptoms of autism and attention deficit hyperactivity disorder...The study - led by researchers from the Center for Research in Environmental Epidemiology (CREAL) in Barcelona, Spain - is published in the International Journal of Epidemiology.