Down’s screening checks for several chromosomal disorders in the fetus. The Down’s syndrome test evaluates the risk of trisomy 21, trisomy 18, and neural tube malformations in the fetus. The Down’s syndrome test measures the levels of human chorionic gonadotropin, alpha-fetoprotein, and free estriol in the maternal blood, along with the mother’s age, weight, last menstrual period, and exposure to toxins and harmful substances during early pregnancy, to determine the risk of congenital disorders in the fetus. Down’s syndrome screening is an important test during pregnancy, and it is recommended that all eligible pregnant women undergo Down’s syndrome screening, and if they are at high or critical risk for Down’s syndrome screening, it is recommended that they go to the Genetic Counseling Clinic at a higher level hospital for counseling, and undergo an amniocentesis test if necessary.