A US study found expectant mothers who take the common pain reliever, acetaminophen, more than six times during their early pregnancies are significantly more likely to have language delay in their baby girls.
Acetaminophen, also known as paracetamol, is the active ingredient in Tylenol, Panadol and hundreds of over-the-counter and prescription medicines.
Most women who complain of aches and pains during pregnancy are usually asked to take paracetamol as a first line pain reliever, which is presumed to be very safe during pregnancy.
However, in the first study of its kind, researchers from the Icahn School of Medicine at Mount Sinai Hospital, New York found an elevated rate of language delay in girls at 30 months old born to mothers who used acetaminophen during pregnancy, but not in boys.
This is the first study to examine language development in relation to acetaminophen levels in urine.
Researchers analyzed 754 women who were between 8 and 13 weeks into their pregnancies.
The study’s participants were asked how many acetaminophen tablets they took between conception and the trial’s initiation.
Their urine was tested for it’s acetaminophen concentration
Language delay defined as the use of fewer than 50 words, was investigated by both a nurse’s assessment and a follow-up questionnaire filled out by participants about their child’s language milestones at 30 months.
Language delay was seen in 10 percent of all the children in the study, with greater delays in boys than girls overall.
However, girls born to mothers with higher exposure — those who took acetaminophen more than six times in early pregnancy — were nearly six times more likely to have language delay than girls born to mothers who did not take acetaminophen.
These results are consistent with studies reporting decreased IQ and increased communication problems in children born to mothers who used more acetaminophen during pregnancy.
Both the number of tablets and concentration in urine were associated with a significant increase in language delay in girls, and a slight but not significant decrease in boys.
Overall, the results suggest that acetaminophen use in pregnancy results in a loss of the well-recognized female advantage in language development in early childhood.
Study author Dr Shanna Swan, PhD, Professor of Environmental and Public Health at the Icahn School of Medicine at Mount Sinai said: “Given the prevalence of prenatal acetaminophen use and the importance of language development, our findings, if replicated, suggest that pregnant women should limit their use of this analgesic during pregnancy.
”It’s important for us to look at language development because it has shown to be predictive of other neurodevelopmental problems in children.”
The findings were published in the journal European Psychiatry.