I'm at 12 weeks Nuchal Translucency Ultrasound - due to my ripe old age of 35 this ultrasound was recommended to check for possible birth defects, specifically Down Syndrome and Trisomy 13 & Trisomy 18. The nuchal translucency ultrasound has approximately an 80% detection rate for down syndrome as well as detect other chromosomal abnormalities and heart defects. The doctor said everything looked good and the results came back very positive. Prior to the ultrasound my estimated (based on age) chance of having a baby with down syndrome was 1 in 250. After the ultrasound my chances are 1 in 4,000. Prior to the ultrasound my estimated chance of having a baby with Trisomy 13 or Trisomy 18 was 1 in 400. After the ultrasound my chances are 1 in 8,000.