Final answer:
A teratogen is an environmental agent that can cause damage to a developing embryo or fetus, resulting in a wide range of birth defects. The potency of the teratogen, the fetus's susceptibility, and the dosage all influence the degree of teratogenicity. Examples include alcohol, tobacco, certain medications, illicit drugs, radiation, and some viruses with alcohol being the leading preventable cause of intellectual disabilities in children in the U.S.
Step-by-step explanation:
A teratogen is defined as any environmental agent—whether biological, chemical, or physical—that can cause damage to a developing embryo or fetus. The adverse impacts of teratogens on a developing baby can be quite severe and include a wide range of birth defects. The degree of teratogenicity depends on multiple factors, such as the potency of the drug as a mutagen, the susceptibility of the fetus to teratogenesis, and the dose of the teratogen.
Certain substances like alcohol, when consumed during pregnancy, can lead to Fetal Alcohol Spectrum Disorders (FASD), which can cause lifelong consequences including but not limited to small head size, abnormal facial features, and a range of developmental problems such as poor judgment, impulse control issues, and learning difficulties. Similarly, tobacco smoking during pregnancy has been linked to a variety of harmful outcomes, including growth and increased risk of perinatal morbidity and mortality.
Other examples of teratogens include prescription and over-the-counter medications, illicit drugs like heroin and cocaine, radiation, and certain viruses such as HIV and rubella. For instance, babies born to mothers who have used heroin during pregnancy may be born with an addiction and require medical intervention to prevent life-threatening withdrawal symptoms.
To ensure normal fetal growth and development, pregnant women are advised to avoid exposure to teratogens, and focus on ample nutrition and proper prenatal care. Understanding the risks associated with teratogens is crucial for preventing birth defects and ensuring the health of the child.