Objective: To study the association between nitrazepam, medazepam, tofisopam, alprazolum and clonazepam treatments during pregnancy and prevalence of different congenital abnormalities (CAs).
Materials and methods: A matched case-control study using cases with CAs and population controls from the dataset of the nationwide Hungarian Case-Control Surveillance of Congenital Abnormalities (HCCSCA), 1980-1996.
Results: Of 38,151 pregnant women who had babies without any defects (population control group), 75 (0.20%) were treated with these five benzodiazepines during pregnancy. Of 22,865 pregnant women who delivered offspring with CAs, 57 (0.25%) had benzodiazepine treatment. The occurrence of five benzodiazepine treatments during the second and third months of gestation, i.e. in the critical period for most major CAs did not show significant differences in matched case-control pairs.
Conclusion: Treatment with five benzodiazepines studied during pregnancy did not present detectable teratogenic risk to the fetus in humans but the amount of information was limited for different CAs.