Patient's question:
My Down syndrome screening 21-trisomy risk value is 1; 170, what is the normal value? Is it high risk if it's above the normal value or high risk if it's below the normal value? Urgent.Doctor's answer:
Guidance: The critical value is 1/275. If it is greater, it is high-risk; if it is less, it is low-risk. It is best to have an amniocentesis test.