During pregnancy, expectant mothers need to go to the hospital on time for relevant prenatal screening tests to reduce the birth of defective babies. Down syndrome screening, also known as prenatal screening for Down syndrome, is an important prenatal screening test. Some expectant mothers would like to know in advance when Down syndrome screening should be conducted?
Down syndrome screening is the process of extracting blood from pregnant mothers, extracting serum, and testing the levels of certain biochemical indicators (such as free estriol, alpha fetoprotein, and chorionic gonadotropin concentration) in the serum. At the same time, it combines multiple factors such as the mother's age, weight, and gestational age at the time of testing to comprehensively determine whether the fetus is at risk of congenital idiocy or neural tube defects.
The time for Down syndrome screening is generally between 15 and 20 weeks of pregnancy, and the best examination time is between 16 and 18 weeks of pregnancy. Doing Down syndrome screening too early or too late can affect the accuracy of the results. Therefore, pregnant mothers must do Down syndrome screening according to the time. If the examination time is missed, it cannot be retested and can only be judged by amniocentesis.
After the pregnant mother completes the Down syndrome screening, if the results show high risk, it indicates that the probability of the fetus suffering from Down syndrome is relatively high. However, this does not necessarily mean that the fetus is a Down syndrome child. At this time, further examination is needed, that is, at 20 weeks of pregnancy, amniocentesis or non-invasive DNA testing should be performed to evaluate. If the results show normal, it means that the fetus is not a Down syndrome child and can continue to conceive.
