The clinical effects on early pregnancy are related to the type of drug, if it is anti-inflammatory drugs have little effect, such as penicillin, azithromycin, cephalosporin, etc., will not affect the growth and development of the fetus. However, antiviral drugs have a great impact and can easily cause fetal malformations, such as ribavirin and acyclovir, etc. Drugs for the treatment of mental illness such as lorazepam and eszopiclone, antifungal drugs such as dacrynic acid and mycophenolate can affect fetal development and in severe cases can easily cause malformations. In the early stages of pregnancy try not to use drugs, if you must use drugs need to choose drugs with few side effects under the guidance of a doctor, after the use of drugs need to be regular maternity checks, need to do Down’s syndrome screening, 4-dimensional ultrasound examination, can determine the fetal development. If the fetal development is normal, the pregnancy can continue, if abnormalities occur, abortion or induction of labor should be promptly, the use of drugs during pregnancy must be cautious, the need for reasonable supplementation of folic acid during pregnancy to prevent fetal malformations.