You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is Which Congenital malformation of the fetus can be diagnosed in first trimester by ultrasound? and explain in detail?
Ans. A. AnencephalyUltrasound can be used to detect anencephaly as early as 10 weeks' gestation. With an abnormal head/trunk ratio and abnormally large orbits, the absence of the superior vault is associated.The length of crown-rump is normal in most anencephalic fetuses.