All pregnant women with one of the following conditions should undergo prenatal teratology testing with the consent of a genetic counseling doctor in the third to fourth month of pregnancy. 1.Pregnant women over 38 years of age: Because of the aging of the eggs, or even more abnormalities, there is a greater risk of producing congenital malformations or congenital stupidity in the fetus. If the husband is over 50 years old, even if the pregnant woman is younger, due to the aging of male sperm, teratology examination should be done. 2.Women who have given birth to anencephaly, spina bifida or other malformed fetus: their risk of having another child with the same kind of abnormality is much higher than that of the average pregnant woman. 3, there are habitual abortion, preterm delivery history or many times the fetus died in the womb of women: often by one or both sides of the couple chromosomal abnormalities caused by another pregnancy, can still appear teratology. 4, there are inborn metabolic function defects in the family, or the pregnant woman herself has given birth to a child with metabolic function defects. 5.Couples married to close relatives. 6, pregnant women in the third trimester of pregnancy, who have suffered from rubella, herpes zoster, herpes simplex, cytomegalovirus disease and other viral infections, due to easy transmission to the fetus malformation, should be teratology examination. 7, early pregnancy has used drugs that can cause fetal malformation, or received radioactive substances, easy to cause fetal malformation. After prenatal genetic counseling, the doctor thinks it is necessary to do teratology examination.