Tylenol is the one of the few over-the-counter pain medications that doctors say is safe for women to use throughout their pregnancy. But a recent study from John Hopkins University points to a link between using the drug when pregnant and increased risks of Attention Deficit Hyperactivity Disorder (ADHD) and Autism Spectrum Disorder (ASD) in baby, reinforcing similar findings from previous studies.
The study differs from those conducted in the past in that it used umbilical cord blood to measure the levels of acetaminophen, the active ingredient found in Tylenol, rather than relying on self-reported data. After testing the blood from 996 babies, researchers found that newborns exposed to the highest levels of acetaminophen right before birth were three times more likely to be diagnosed with ADHD or ASD. They note, though, that it’s impossible to tell if this was due to the time the drug was taken or the reason it was taken.
The study also found that, of the 996 babies tested (all of which had acetaminophen in their umbilical cord blood), by the time they were approximately 10 years old, 25.8 percent had been diagnosed with ADHD, 6.6 percent with ASD and 4.2 percent with both.
“Cord biomarkers of fetal exposure to acetaminophen were associated with significantly increased risk of childhood ADHD and ASD in a dose-response fashion,” the study states. “Our findings support previous studies regarding the association between prenatal and perinatal acetaminophen exposure and childhood neurodevelopmental risk and warrant additional investigations.”
Previous studies have also found a link between acetaminophen and ADHD, including one study done in 2016 that surveyed close to 8,000 women in the UK. It found that women who used the drug when they were 18 to 32 weeks pregnant were more likely to report behavioral issues, such as hyperactivity, in their kids. Similarly, a study conducted by Norwegian researchers the following year in 2017 reported a link between consecutive use of acetaminophen during pregnancy and ADHD.
While these studies have found a link, they haven’t found a definitive cause-and-effect relationship between the two—and doctors do still deem Tylenol safe to take during pregnancy. So, don’t despair yet! Just make sure to talk to your doctor about how and when to take it.