I just wanted to post my experience for those who may have just gotten a high NT on their prenatal screening test.
at 12 weeks I went in for the prenatal screening test to find out that I was having twins! which was very exciting for us since twins are not in our family at all and we were not taking any fertility treatments. The next day we got a call from our doctors office that my doctor needed to see me right away, I was then told that my NT on baby A was 3.3mm (baby B was 1.3mm), that that was abnormal and that I would need to see a genetic counsellor immediately. I was devasted, such good news only to be shot down with bad news the next day. We were told that 3.3mm is borderline and it only increased the risk of having DS, but was by no means definitive. Then at the 18week anatomy scan they found 2 soft markers, one in the brain and one on the heart, which was again not definitive but increased our chances a bit more. We chose not to do the amnio because I did not want to risk a miscarriage, twice the baby means twice the risk. SO, we were booked in for a fetal echocardiogram which showed that baby B had a small artery where there should have been a large one, nothing serious but there all the same. After 25 weeks of waiting and worrying, I gave birth to Aiden (Baby A) who had to spend 8 hours in the nicu to get an echocardiogram done and had some rapid breathing, he turned out to be 100% ok. No DS, no heart problems, perfect. All that worrying for nothing. I hope our story can give some comfort to others who might also have had some worrying test results, even with all these indicators pointing to DS our baby was completely healthy. I wish I hadn't taken the screening test in the first place, the worrying almost took the fun out of having twins.