Does Quad Screening detect all chromosome abnormalities?
No. There are many different chromosome abnormalities; approximately half are trisomy 21 or trisomy 18. Quad screening identifies approximately 80% of fetuses with trisomy 21 and 67% of fetuses with trisomy 18. Diagnostic testing (CVS or amniocentesis) will identify 99% of all chromosome abnormalities. These procedures have a small risk of pregnancy loss.
