An early anatomy ultrasound is a check of the baby from “head to toe” making sure all the major structures are developing normally. This is standard pregnancy care for all pregnant women even if parents do not wish to have Down syndrome screening.
A Nuchal Translucency Ultrasound can only be performed between 11 and 13 weeks of pregnancy. A small pouch of fluid at the back of the baby’s neck “the nuchal translucency” is measured. The nuchal translucency gets thicker with some genetic and structural problems.
At O&G we place a lot of importance on carefully checking the major organs and structures even though the baby is less than 10cm in length. These structures will be reviewed in more detail at the morphology ultrasound (18 to 20 weeks) when the baby is bigger.
Do I need a full bladder?
It is helpful to arrive with a full but comfortable bladder. If you are having a nuchal translucency ultrasound, please to drink a big glass of water (about 500mls) 1 hour prior to the appointment
Combined First Trimester Down Syndrome Screening
“Combined Screening” uses a combination of the nuchal translucency measurement from the ultrasound, a blood test from the mother and the mother’s age to give a risk for Down syndrome. It also gives a risk for two other less common genetic abnormalities called Edwards syndrome and Patau syndrome.
It picks up Down syndrome about 90% of the time. However 5% of women with a normal baby have a high risk result. If your result is high risk for a genetic problem you will be offered another test to determine if the baby has Down syndrome.
Ultrasound: between 11 and 13 +6 weeks to measure nuchal translucency and check fetal size and anatomy.
Blood test: from 9 to 14 weeks to measure for two pregnancy proteins which change with Down syndrome (PAPP-A and βhCG).