Fetal growth and adverse birth outcomes in women receiving prescriptions for acetaminophen during pregnancy

We studied the association between acetaminophen exposure during pregnancy and the prevalence of congenital abnormalities and fetal growth. Our study included 123 women who had received a prescription of acetaminophen during pregnancy and/or 30 days before conception and 13,329 controls who did not receive any prescription at all. We found more malformations among those wh o received a prescription with an odds ratio of 2.3 (95% CI 1.0-5.4), but t he type of malformations did not indicate a causal link. When restricting t he study to first time pregnancies, we identified 58 women who received a p rescription of acetaminophen during pregnancy and 30 days before conception and 7472 controls. We found no excess risk of malformation [OR = 0.7 (95% CI 0.1-5.5)], and no evidence that acetaminophen should influence fetal gro wth.