Many expectant mothers need medication during pregnancy for one reason or another. For the health of your child, please pay attention to the effects of different drugs on the fetus. The U.S. Food and Drug Administration (FDA) classifies drugs into five categories, called the pregnancy classification of drugs, or FDA classification, based on the different degrees of teratogenic risk they pose to animals and humans. Class A: Drugs used during early pregnancy that have not been shown to be harmful to the fetus in controlled clinical studies and whose risk is minimal, such as multivitamins. Class B: Drugs that have not been shown to be harmful to the fetus in animal studies, but have not been studied in controlled clinical studies; or drugs that have been observed to be harmful to the fetus in animal studies, but have not been confirmed in controlled clinical studies. For example, some antibiotics, penicillins, cephalosporins, etc. Category C: The adverse effects on fetus have been found in animal experiments, but there is no adequate proof in human or adequate controlled studies in animal experiments. For example, aspirin, etc. Class D: If there is evidence of harm to human fetus, but there is no clinical alternative drug, it should be used after weighing the pros and cons. For example, some antibiotics and hormones. Class X: These drugs are contraindicated in pregnancy because of their obvious teratogenic effects on both animals and humans, and their harmful effects far outweigh any beneficial effects they may obtain. Such as anti-cancer drugs, birth control pills, etc.