Nitrofurantoin and congenital abnormalities

To study human teratogenic potential of oral nitrofurantoin treatment during pregnancy.

Pair analysis of cases with congenital abnormalities and matched population controls in the population-based dataset of the Hungarian Case-Control Surveillance of Congenital Abnormalities, 1980-1996.

Of 38,151 pregnant women who had newborn infants without any congenital abnormalities (population control group), 774 (3.4%); of 22,865 case pregnant women who had newborns or fetuses with congenital abnormalities, 1079 (2.8%) and of 812 pregnant women who had newborns or fetuses with Down's syndrome (patient controls), 23 (2.8%) pregnant women were treated with nitrofurantoin. The above differences between population controls and cases may be connected with recall bias, because the case-control pair analysis did not indicate a teratogenic potential of nitrofurantoin use during the second and the third months of gestation, i.e. in the critical period for major congenital abnormalities.

Treatment with nitrofurantoin during pregnancy does not present detectable teratogenic risk to the fetus.