Benzodiazepines in pregnancy--academical debate or teratogenic risk?

Benzodiazepines are presently the most widely prescribed drugs. They are considered as safe drugs although there is appreciable evidence from animal experiments as well as from epidemiological evaluations that they act as teratogens. The pertinent literature is subjected to a synopsis with results from pharmacological, biochemical and behavioral research. Recent views of the mechanisms of teratogenic action serve to propose several points of attack where benzodiazepines can disturb the development of the central nervous system. This attack can take place during organogenesis, during early differentiation of neural anlagen after neural tube closure or during biochemical differentiation of the brain. It is suggested that intake of benzodiazepines at any time during pregnancy may result in visible malformations, in functional deficits or in behavioral anomalies of the exposed children.