The American College of Obstetricians and Gynecologists disputed President Donald Trump’s announcement linking Tylenol use during pregnancy to autism, and slammed the administration’s guidance as “irresponsible” and “unsettling” in a Monday statement.

“Today’s announcement by HHS is not backed by the full body of scientific evidence and dangerously simplifies the many and complex causes of neurologic challenges in children,” ACOG President Steven J. Fleischman said. “It is highly unsettling that our federal health agencies are willing to make an announcement that will affect the health and well-being of millions of people without the backing of reliable data.”

Fleischman went on to note that “not a single reputable study has successfully concluded that the use of acetaminophen in any trimester of pregnancy causes neurodevelopmental disorders in children.” He added that the studies often cited as evidence face “methodological limitations,” including issues with self-reported data and a lack of control for confounding variables.

On Monday, Trump also repeatedly argued that there’s no “downside” if people abstain from Tylenol use while pregnant, a claim that experts contested as well. If left untreated, maternal fever and pain can be harmful, Fleischman said.