What is second-trimester triple serum screening?

Generally, the second-trimester triple serum screening is a method for screening Down syndrome by drawing blood to monitor the peripheral blood of pregnant women. The specific analysis is as follows:

The second-trimester triple serum screening is a test that evaluates the risk of fetal Down syndrome by measuring the levels of specific biomarkers in the mother's blood between 16 and 18 weeks of pregnancy. This screening typically measures alpha-fetoprotein (AFP), human chorionic gonadotropin (hCG), and unconjugated estriol (uE3). Alpha-fetoprotein is a protein produced by the developing fetus. Abnormal AFP levels may be associated with neural tube defects such as spina bifida. Human chorionic gonadotropin is a hormone produced by the early placenta, and abnormal hCG levels may indicate chromosomal abnormalities. Unconjugated estriol is the main estrogen synthesized by the placenta, and abnormal uE3 levels may be linked to Down syndrome and other chromosomal abnormalities. By measuring the levels of these three markers in the maternal blood and combining them with the mother’s personal information, the probability of the fetus having Down syndrome can be calculated.

If the screening results indicate a high risk, pregnant women are advised to promptly visit a正规 hospital to confirm whether chromosomal abnormalities exist through procedures such as amniocentesis or non-invasive prenatal testing (NIPT) using DNA technology.