Abstract: The medical institutions encroached upon the patient’s right to know in the prenatal examination and diagnosis, resulted in the loss of chance of termination of pregnancy, birth defects and serious damage to the parents, so should bear tort liability. Damage compensation will not harm the dignity of the child, will not increase the defensive medical treatment, but will help reduce and disperse the risk of prenatal diagnosis. Specia maintenance costs caused by birth defects should be supported and mental damage compensation is an applicable rule.