How to interpret the Tang screening results?Down syndrome screening (Down syndrome screening) is an important prenatal check-up item during pregnancy. It assesses the risk of the fetus suffering from chromosomal abnormalities such as Down syndrome by detecting maternal serum markers and ultrasound data.The result is divided intohigh risk, critical risk, low riskCategory three needs to be comprehensively judged based on maternal age, gestational age and other factors.If the result is high risk or critical risk, further diagnosis needs to be made through non-invasive DNA or amniocentesis.

Paragraph 1: Result Classification and Initial ResponseTang screening reports usually include three core indicators: AFP (alpha-fetoprotein), hCG (human chorionic gonadotropin) and uE3 (free estriol).The risk value is presented as a ratio, such as 1:1000 (low risk) or 1:100 (high risk).Important notes:High risk is not a confirmed diagnosis, so you need to stay calm and follow the doctor's instructions for re-examination; low risk does not mean absolute safety, and needs to be comprehensively evaluated in conjunction with other examinations.

Paragraph 2: Indicator Analysis and Influencing FactorsLow AFP may indicate chromosomal abnormalities in the fetus. Abnormally elevated hCG should alert you to Down syndrome, and reduced uE3 levels may also be associated with risks.Maternal age (the risk is significantly increased when ≥35 years old), weight, gestational age calculation errors, etc. will all affect the accuracy of the results.For example, errors in gestational age estimation may lead to false positives, and gestational age needs to be verified through NT ultrasound.

Paragraph 3: Follow-up inspection optionsIf Tang screening results are abnormal, it is usually recommended toNon-invasive DNA testing(accuracy rate is about 99%) oramniocentesis(gold standard but invasive).Non-invasive DNA is suitable for people at borderline risk, while sheep biopsy is suitable for people who are at high risk or have a family history of genetic disease.It is necessary to fully communicate the pros and cons with the doctor before the examination. For example, there is a 0.5% risk of miscarriage in amniostomy, which needs to be weighed carefully.

Paragraph 4: Psychological adjustment and scientific cognitionAvoid excessive anxiety when faced with abnormal results.Statistics show that only about 2%-5% of pregnant women at high risk of Tang screening are eventually diagnosed.Genetic counseling can help you understand the true risks and make decisions together with your family.At the same time, attention is paid to nutrition during pregnancy (such as folic acid supplementation) and regular prenatal check-ups to ensure fetal health in multiple dimensions.

Summary and data referenceTangScreen is a screening tool rather than a diagnostic tool, and the results need to be viewed rationally.The following is a risk ratio reference table:

Quote sources:
1. Chinese Medical Association's "Guidelines for Pre-Pregnancy and Pregnancy Health Care"
2. American College of Obstetricians and Gynecologists (ACOG) Pregnancy Screening Guidelines
3. BGI, Berry and Kang and other manufacturers provide non-invasive DNA testing (product name: NIPT)
4. Data reference: Peking Union Medical College Hospital 2022 Prenatal Screening Statistical Report