Introduction
Teratogen is broadly defined as an environmental agent capable of causing abnormal prenatal variation in form or function. In other words, it can be any environmental factor that can produce a permanent abnormality in structure or function of an embryo or fetus or restriction of growth of an infant (Gilbert-Barness, 2010). In prenatal life, exposure to teratogens may even lead to death of the embryo or fetus. It is estimated that approximately 15% of all congenital structural abnormalities observed in a child are due to exposure to some kind of teratogens during the prenatal life (Brent, 2001). A larger number of ...