Exposure to paracetamol during pregnancy seems to increase the risk of language delay in girls, but not boys, at 30 months of age, according to European Psychiatry.

Researchers enrolled 754 women in Sweden between weeks eight and 13 of pregnancy. At enrolment, the women were asked how many paracetamol tablets they had taken since conception and urinary paracetamol concentrations were measured. The authors defined language delay as using fewer than 50 words at 30 months (based on parental reports).

Between conception and enrolment, 59.2 per cent of pregnant women reported taking paracetamol: 23.4 per cent took one to three tablets, 18.2 per cent four to six tablets and 17.6 per cent more than six tablets.

Boys were more likely to show language delay than girls (12.6 and 4.1 per cent respectively) but the number of paracetamol tablets and the urinary paracetamol concentration were associated with language delay in girls, not boys.

The prevalence of language delay rose from 1.3 per cent among girls born to women who did not take paracetamol during the first trimester to 8.5 per cent in those who took more than six tablets. After adjusting for confounders, girls born to mothers who reported taking more than six paracetamol tablets were about six times more likely to show language delay compared to those who did not take any paracetamol. The increased risk with one to three and four to six tablets did not reach statistical significance.

Girls born to mothers whose urinary paracetamol was in the highest quartile were more than 10 times (odds ratio 10.34) more likely to show language delay compared to those in the lowest quartile. The increased risk in the second and third quartile did not reach statistical significance.

“Given the prevalence of prenatal [paracetamol] use and the importance of language development, our findings, if replicated, suggest that pregnant women should limit their use of this analgesic during pregnancy,” the authors say.

It is important to look at language development because it has shown to be predictive of other neurodevelopmental problems in children, they add.

^{DOI:10.1016/j.eurpsy. 2017.10.007}