Final answer:
The greatest risk of birth defects and miscarriage is during the embryonic stage (3rd to 8th week after fertilization), not the fetal stage. Therefore, the statement is false.
Step-by-step explanation:
The statement that the greatest risk of forming birth defects and miscarriage occur in the fetal stage is false. The risk of these birth complications is greater during the embryonic stage, which occurs from the third week to the eighth week after fertilization. During this phase, the major organs and body structures begin to form. Disturbances or damage in this period can cause structural defects or miscarriage.
Learn more about Birth Defects and Miscarriage