When it comes to taking painkillers when you’re pregnant, acetaminophen (a.k.a. Tylenol) is just about the only option that’s considered safe for the growing baby. And between the headaches, swollen feet and lower back pain, being able to take painkillers can be a godsend.
However, a new study published in the journal Pediatrics has linked acetaminophen use during pregnancy with an increased risk of having a child with an attention deficit hyperactivity disorder (ADHD) diagnosis down the line.
But don’t panic or throw out your pills yet. The increased risk mostly applies to pregnant women taking acetaminophen regularly and for a long period of time, as in more than 29 days. In fact, women who used Tylenol for less than seven days actually had a decreased risk of having a child with ADHD.
The study looked at data from the Norwegian Mother and Child Cohort Study, which involved 112,973 children, 95,242 mothers and 75,217 fathers from all over Norway who filled out questionnaires given to them throughout pregnancy and after delivery.
About half of the mothers used acetaminophen, but only 3.3 percent of mothers took the drug long-term. For these mothers, the risk of an ADHD diagnosis for their child was doubled, which lead author Eivind Ystrøm says is alarming enough that physicians should be aware of the risk.
“We’re not saying that [pregnant] should not use Tylenol,” said Ystrøm. “We’re saying that they should consult their doctor [for].”
The study also found that fathers who took acetaminophen before conception had an increased risk of ADHD diagnosis in their offspring too. However, Ystrøm said there was not enough data to make any recommendations for fathers regarding acetaminophen use.
The researchers aren’t sure if the increased risk on the fathers’ side is due to sperm being altered by the drug itself or due to the underlying conditions that made the dads-to-be take acetaminophen in the first place. “We just have to admit that we really don’t know,” said Ystrøm.
There also isn’t enough data to say that acetaminophen use during pregnancy causes ADHD. Though this study found a link between the two, researchers are still unsure what effect the drug may be having in the body that could cause the increased risk.
For now, further research is needed to figure out what exactly is going on, but it’s important not to rule out taking acetaminophen when you're pregnant. You should continue to use it for pain relief and treating fevers because high fevers have been proven dangerous to a baby early in pregnancy—just make sure it's at the lowest dose possible for the shortest amount of time.
“We do not warn women from using acetaminophen when they need it—especially for fever but also for pain relief,” says Ystrøm. “It’s just that for long-term use, they should not do that alone.”