What is the normal range for唐screening values?
Dec 29, 2022
Source: Cainiu Health
Dr. Lv Aiming
Introduction
Down syndrome screening is a prenatal screening test performed during the second trimester. The cutoff for Down syndrome screening is 1/222; a result below 1/222 is considered low risk, while a value above this threshold indicates higher risk, warranting further testing such as amniocentesis or non-invasive DNA testing. Down syndrome screening involves collecting a blood sample from the pregnant woman between 16 and 22 weeks of gestation to measure levels of certain markers in her blood.
In daily life, some people pay special attention to their physical health and regularly go to the hospital for medical checkups to monitor whether any of their health indicators are out of range. One common item that appears on体检 reports is the "Down syndrome screening value." So, what Down syndrome screening value is considered within the normal range?
What Down Syndrome Screening Value Is Considered Normal?
Down syndrome screening is a test performed during the second trimester of pregnancy. The threshold for Down syndrome screening is 1/222. A normal result means the risk value is less than 1/222; values higher than this indicate an increased risk, requiring further testing such as amniocentesis or non-invasive prenatal DNA testing (NIPT). Down syndrome screening involves collecting a blood sample from the pregnant woman between weeks 16 and 22 of pregnancy to measure levels of alpha-fetoprotein (AFP), human chorionic gonadotropin (hCG), and unconjugated estriol (uE3). These results, combined with the mother’s weight, age, and gestational age, are used to comprehensively assess the risk of fetal Down syndrome, helping reduce the birth rate of children affected by this condition and promoting healthier pregnancies.
Down syndrome screening includes both early and mid-trimester screenings. Early screening is conducted around weeks 10–14 of pregnancy and primarily involves an NT (nuchal translucency) ultrasound to evaluate the fetus's risk of Down syndrome or congenital heart defects. Mid-trimester screening should be performed between weeks 14 and 20 of pregnancy, during which blood tests measure serum levels of human chorionic gonadotropin and unconjugated estriol in the expectant mother. Together with maternal physical characteristics and gestational age, these data are analyzed along with the mother’s age to assess fetal health.
Everyone should pay close attention to their personal health. If any abnormalities are detected, it is important to visit a hospital promptly for examination and treatment to avoid adverse effects on health. We hope this information has been helpful. Wishing you good health and a happy life!
