Question

What are all the tests which can be used to screen for *Trisomy 21* (& other aneuploidy)? Which test is the MOST accurate (highest true + rate)?

Answer 1

Screening tests for Trisomy 21 (Down syndrome) and other aneuploidies include ultrasound, blood tests, and noninvasive prenatal testing (NIPT). The most accurate test is NIPT.

Step-by-step explanation:

Screening tests for Trisomy 21 (also known as Down syndrome) and other aneuploidies include:

• Ultrasound: This non-invasive test uses sound waves to create images of the developing fetus. It can detect certain physical abnormalities associated with Trisomy 21, such as increased fluid at the back of the neck (nuchal translucency).
• Blood tests: These tests measure levels of certain substances in the mother's blood, such as pregnancy-associated plasma protein-A (PAPP-A) and human chorionic gonadotropin (hCG). Abnormal levels can suggest a higher risk of Trisomy 21.
• Noninvasive prenatal testing (NIPT): This blood test analyzes fetal DNA in the mother's blood to detect chromosomal abnormalities, including Trisomy 21. It is highly accurate and has a high true positive rate.

The most accurate test for screening Trisomy 21 and other aneuploidies is Noninvasive prenatal testing (NIPT). It has a high true positive rate and can detect a high percentage of cases with Trisomy 21.