My best friend was told she had 5/8 markers for down syndrome and offered her the amino to confirm. She chose not to do it and take her chances because an amino can increase your chance of miscarriage. At a follow up ultrasound they thought they saw a sist on the baby's brain which could indicate Edwards Disease which is the opposite of down syndrome but worse. Her chances were 1/100 of either DS or Edwards Disease. In May 2011 she gave birth to an absolutely perfect baby girl. She used her time research and prepare "in case". Another girlfriend of mine had no risk factors and 2 ultrasounds with no problem. She was in labor for 15 hours before they sent her for C section because the baby was sideways and wouldn't turn. It wasn't until baby was born that she found out baby had down syndrome. I think the only "for sure" is the amnio. Good luck and I hope everything works out for you.
they told me mine was positive too... I have a 1:810 We talked to the dr after and he told me I have a greater chance of getting hit by a car. It is just a marker that that shows its a higher risk. Doesn't mean it actually has downs. Mine was barely even over the norm but they have to tell you its positive just in case you want to do the amio testing.
My Dr also said that the measurements on the neck are a better indicator. As long as those were fine he told me not to worry.
You don't need to worry. The thing that makes me feel better is to put the numbers into view. If you had 850 kids on average only 1 would have downs syndrome. Those aren't bad odds. If it was 1 in 4 then I would be concerned. There was a lady awhile ago who had 1:8 I believe. So 1:850 is not likely to have it.