What are examples of teratogens and what do they do?

Teratogens are anything potentially harmful to a developing fetus. These include but are not limited to: nicotine, alcohol, drugs, radiation, AIDS, rubella, etc. These cause structural abnormalities and abnormal cell masses to develop in the fetus which can lead to serious birth defects. Some examples of these are
* physical and cognitive developmental delays
* cleft palate * abnormal facial characteristics * mental retardation * growth defects * heart defects * abnormalities of the fingers and nails * impaired fine and gross motor skills * hearing loss * vision loss/blindness
* deformed and paralyzed limbs * small head size and brain