Evo sto pise na babycenter linku, ne znam moze li se uzeti za pouzdanu informaciju, malo sam gledala i po drugim mjestima, informacije su otprilike iste. S napomenom da su invazivni testovi potrebni kako bi se dobila sigurna informacija. Meni je ovo dovoljno da se ne "zamaram".




You may have read that the results of this test are 80 percent accurate in detecting your risk of having a baby with Down syndrome. That means that if you're carrying a baby with DS, there's an 80 percent chance that the test will pick that up and give you a "screen positive" result indicating that further testing is recommended. It also means there's a 20 percent chance that the test will miss the DS and give you a "screen negative" result, in which case diagnostic testing won't be recommended.

Note: This does not mean that a "screen positive" baby has an 80 percent chance of having DS. It just means that 80 percent of babies who have DS will have screening results that are suspicious enough to recommend diagnostic testing. And 20 percent of babies who have DS will be shown to be at normal risk — that is, the results will be falsely reassuring.

The test also has a 5 percent false positive rate. A "false positive" result is one that suggests there may be a problem when, in fact, there is no problem. In this case, a 5 percent false positive rate means that 5 percent of the babies with normal chromosomes who are tested will be "screen positive" — the test will show them to have an increased risk even though they're normal. Based on this "false positive" result, their mothers may go ahead with invasive diagnostic testing that they otherwise might not have. (And they'll probably worry more, too, until a CVS or amnio shows that their baby is fine.)