Hi, I am 35 years (will be 36 when I deliver) old and 14 weeks pregnant with fraternal Twins. This is my second pregnancy, I had a miscarriage the first time. I just had my prescreening test for down syndrome, trisomy 13 and 18. I got the results back with a 1:76 chance for twin A and a 1:56 chance for twin B to have down syndrome. I know these are prescreening test and only provide possibilities based on blood levels, age, measurements, etc. My question is for anyone who in having/had twins, how accurate are these results? I have read that with twins it's a lot harder to determine the prescreening results because there is no way of telling what is coming from which baby. The results were based on the higher measurement of the nuchal translucency which was 2.5 and 2.6 for the babies and the blood test. Those measurements are within the normal range although on the upper end. I would love to hear from anyone who has received similar results and if you decided to have amniocentesis after receiving the results.