Screening tests for fetal malformations are available at different stages of pregnancy. Pregnant women can have NT test at 11-13 weeks of pregnancy, Down’s syndrome screening at around 20 weeks of pregnancy and fetal 4D ultrasound major screening at 22-24 weeks of pregnancy, so different tests are available to screen for malformations between 3 and 6 months of pregnancy. At 11-13 weeks of pregnancy, NT test can check the embryonic cervical zona pellucida to determine the risk of malformation. At 16-18 weeks of pregnancy, fetal Down’s syndrome screening is performed to exclude fetuses at high risk for trisomy 21, trisomy 18 and fetal neural tube developmental malformations. After 18 weeks of pregnancy, amniocentesis can also be done directly to check for chromosomal abnormalities. 4D ultrasound screening is performed from 20 to 26 weeks of pregnancy to check for fetal malformations in appearance or structural malformations of organs and to rule out fetal kidney, heart, neural tube and five senses malformations. Among them, fetal Down’s syndrome screening and fetal 4D ultrasound screening are two important malformation screening tests during pregnancy. In addition, women should also undergo premarital medical examination and start taking folic acid supplements in the first trimester of pregnancy, and avoid exposure to adverse environment and drugs during pregnancy to prevent fetal malformations.