Any pregnant woman that pay close attention to fetal health. Tang is asked for integratedly is tall hair sex (incidence of a disease is 1/800 about) , abiogenesis sex (any pregnant woman all give birth to Tang to ask for a baby integratedly likely) disease, cannot prevent beforehand. The conditional pregnant woman that pays close attention to fetal health should is pregnant early metaphase undertakes Tang asks for a sieve integratedly to check.