Effect of sodium valproate on rat embryo development in vitro

Teratogenic effects of the anticonvulsant drug valproic acid (VPA) on the development of rat embryos during early stage of organogenesis were studied using whole embryo culture technique. Embryos with 0-3 somites were exposed in culture to 10, 50 and 100 μg/ml VPA. Growth and development were retarded in embryos exposed to 50 and 100 μg/ml. Drug induced anomalies included open neural tube, irregular somites, and asymmetrically enlarged forebrain. The "no-observed-adverse-effect-level" (NOAEL) was 10 μg/ml VPA.