The given blank can be filled with alcohol or drugs.
Explanation:
Birth defects refer to the functional or structural abnormalities found at the time of birth, which leads to mental or physical disability. Some are even fatal. There are various reasons for birth defects like genetic issues and the environmental factors that a woman gets exposed to at the time of pregnancy like using alcohol or drugs at the time of pregnancy.
There are two prime kinds of birth defects. These are functional and structural birth defects. The structural birth defects are associated with an issue with the parts of the body, like cleft palate, cleft lip, and defects in heart, abnormal limbs, and others. On the other hand, the functional birth defects are associated with an issue with how a part of the body or systems of body functions.