A new study is raising new concerns about the use of acetaminophen during pregnancy.Acetaminophen —sold under brand names like Tylenol— has long been considered the safest pain reliever for expectant moms.But a major review of the evidence finds prenatal exposure to the drug may increase the risk of neurodevelopmental conditions, including autism spectrum disorder and ADHD.Researchers analyzed data from 46 published investigations involving more than 100,000 mother–child pairs across multiple countries.Overall, they found a positive link between acetaminophen and neurodevelopmental conditions in offspring.The researchers say acetaminophen can pass through the placenta and may trigger oxidative stress, disrupt hormones, or alter gene expression —all of which could affect fetal brain development.One of the study authors, says: “Given the widespread use of this medication, even a small increase in risk could have major public health implications.”The authors recommend time-limited, medically supervised use of acetaminophen during pregnancy, updated clinical guidance on the benefits and risks of the drug and more research to find safer alternatives.They also stress pregnant women should never stop or change medications without talking to their doctor.Source: BMC Environmental HealthAuthor Affiliations: Mount Sinai Hospital, University of California, Los Angeles, University of Massachusetts Lowell, Harvard T.H. Chan School of Public Health .Sign up for our weekly HealthDay newsletter