(RxWiki News) Acetaminophen is the most common over-the-counter pain reliever in the United States, and is generally considered safe for pregnant women to use. A new study, however, showed that the medication may affect a child's behavioral development.
A recent study found that maternal acetaminophen (most commonly sold as Tylenol) use during pregnancy increased the risk of behavioral problems for the offspring during childhood.
The researchers also found that the risk increased when mothers used acetaminophen in more than one trimester during pregnancy.
They concluded that more research is needed to determine if there is a cause and effect relationship between the use acetaminophen during pregnancy and later behavioral problems in children.
"Talk to your doctor before taking any medication during pregnancy."
The lead author of this study was Jørn Olsen, MD, PhD, from the Institute of Public Health at the University of Aarhus in Denmark and the Department of Epidemiology in the Fielding School of Public Health at the University of California, Los Angeles.
The study included 64,322 mother/child pairs who were enrolled at six to 12 weeks of pregnancy in the Danish National Birth Cohort Study from 1996 to 2002.
All of the mothers reported whether or not they had used acetaminophen during pregnancy.
When the children were 7 years old, the mothers reported whether or not their child had exhibited any signs of ADHD-related behavior and whether or not they had experienced behavioral problems themselves when they were children.
ADHD-related behaviors include inability to pay attention, hyperactivity, impulsivity and motivational/emotional disregulation.
The researchers also identified cases of hyperkinetic disorder (a severe form of ADHD) from national hospital records, as well as ADHD medication prescription use.
The findings showed that 36,187 (56 percent) of all the mothers reported using acetaminophen during pregnancy.
The children of mothers who used acetaminophen during pregnancy were 37 percent more likely to be diagnosed with hyperkinetic disorder (HKD) compared to the children of mothers who did not use acetaminophen while pregnant.
Acetaminophen use during pregnancy increased the chances of a child being prescribed ADHD medication by 29 percent compared to no acetaminophen use during pregnancy.
The researchers determined that children of mothers who used acetaminophen during pregnancy were 13 percent more likely to exhibit ADHD-like behaviors at age 7 compared to the children of mothers who did not use acetaminophen while pregnant.
These risks were stronger for the children of mothers who reported acetaminophen use during more than one trimester of pregnancy.
The researchers discovered that these findings were independent of infection during pregnancy, the mother's mental health history, demographics (age, race, sex), smoking status or physical health problems during pregnancy.
The authors noted a few limitations of their study. First, the researchers did not have data on ADHD medication dosage or number of pills taken. Second, most of the data was self-reported. Third, some of the mothers could not specify which trimester they used acetaminophen.
This study was published on February 24 in JAMA Pediatrics.
The Danish Medical Research Council provided funding.