ABSTRACT
Many chemicals cause a variety of pre-and post-natal developmental abnormalities and also interfere with mating and conception. Chemicals that induce structural malformations, physiological dysfunctions, behavioral alterations, and deficiencies in the offspring, at birth or in the immediate post-natal period, are referred to as
teratogens
. Most chemicals are not extensively screened for their teratogenic potential, principally because of the many toxicity tests that are already required. Thus, most pharmaceutical and chemical companies do not routinely screen therapeutic drugs or industrial chemicals, respectively, for potential embryotoxicity during preclinical phases. Chemicals not destined to be used clinically are generally not subjected to teratogenic testing.
