Normally, a grand mal test is done at 24-28 weeks of pregnancy. The grand mal test is to go to the hospital for 4D ultrasound. Through the ultrasound, we can determine whether the fetus has any malformation, and we can see whether the fetus is congenital spina bifida, anencephaly, congenital heart disease, abdominal wall defect, abdominal wall hernia, whether there is cleft lip and palate and limb malformation. The 4D ultrasound large screening test is a relatively important test in pregnancy, and you need to make an appointment at the hospital in advance to do the test, and it is to go to the hospital at the appropriate time to do the test. If there is any fetal abnormality after the examination, it must be treated according to the situation, especially for patients with abnormalities in early and mid-term Down’s screening, and it must be done well during this period.