Fetuses are usually tested around 3 months for NT, Early Down’s screening can be done at 10-13+6 weeks of gestation, and Intermediate Down’s screening can be done at 15-20+6 weeks of gestation. Ultrasound to detect malformations is needed at 20-24 weeks of pregnancy. A woman can have an NT test at 11-13 weeks of pregnancy, which is the third trimester of pregnancy, to evaluate the fetus for Down syndrome by measuring the thickest part of the subcutaneous echogenic hyaline layer in the nuchal region of the fetus by ultrasound. Early Down’s screening can be tested at 10-13+6 weeks of gestation, and midterm Down’s screening can be performed at 15-20+6 weeks of gestation to determine the risk factor of the fetus for congenital stupidity and neural tube defects. If the results are abnormal when Down’s screening is performed, further non-invasive DNA or amniocentesis testing is required to ensure normal fetal development. Ultrasound for detecting malformations is needed from 20 to 24 weeks of pregnancy, and based on the results of the test, it is able to rule out malformations in the development of the internal organs of the fetus, malformations in the development of the face, and so on. Pregnant women need to take regular pregnancy tests during pregnancy to observe the growth and development of the fetus. During pregnancy, you need to pay more attention to avoid smoking and drinking, and stay away from second-hand smoke. Strengthen the nutritional intake of the diet, eat more fresh fruits and vegetables and lean meat. Pay attention to more rest, at the same time should be relaxed, avoid tension, anxiety, any discomfort should be timely to the hospital, the doctor clear diagnosis, and cooperate with the doctor to deal with the symptoms.