In your own words, explain why exposure to teratogens during the embryonic period carries the greatest risk for developmental abnormalities?

Reason as exposure to teratogens during the embryonic period carries the greatest risk for developmental abnormalities:

Teratogens are those substances that causes functional or physical abnormalities when the pregnant women are exposed to it. The are four types of teratogens namely,

metabolic conditions physical agents drugs or chemicals infections

Generally, the abnormalities occurs during the third to eighth week of pregnancy i. e the period when the major organs of the fetus develop. They can also lead to the complications like miscarriage, preterm labors or spontaneous abortions.

Some of the types of tranquilizers namely, lithium and phenothiazine are considered to be teratogens. Most of the congenital malformations are of unidentified origin, but the teratogens that are known and evaluated include maternal illnesses and infections, drugs, metal toxicity, or physical factors (for example radiation).