Teratogenic means relating to or causing developmental malformations. In common parlance, these agents cause birth defects, some minor, some horrific. Many different kinds of agents can act as teratogens. Some examples include: | Teratogenic means relating to or causing developmental malformations. In common parlance, these agents cause birth defects, some minor, some horrific. Many different kinds of agents can act as teratogens. Some examples include: |