Step-by-step explanation:
A teratogen can be defined as the any chemical substance which is can cause harm in the body or brain of the fetus.
The nicotine and smoking are dome of the teratogens which increases the risk of low birth, ADHD, respiratory infections and SIDS.
Taking such substance during the time of pregnancy can increase the chances of disease in the baby.
A pregnant lady should not be in direct contact with certain chemicals that are teratogenic in nature.