Passage: The pregnant mother plays a critical role in the development of the embryo and fetus. She must avoid toxic substances such as alcohol, which can damage the developing offspring. She must also provide all the nutrients and other substances needed for normal growth and development. Most nutrients are needed in greater amounts by a pregnant woman, but some are especially important, including folic acid (vitamin B 9 ), calcium, iron, and omega-3 fatty acids. Answer: toxic substances
What should a pregnant woman avoid while pregnant?