This scan is performed usually before 11 weeks to confirm the viability of the pregnancy, which is done by seeing the heart-beat of the baby. It also helps to date the pregnancy and to diagnose multiple pregnancies, if present.
Combined Down Syndrome Screening (Nuchal Translucency Scan combined with blood test)
The first trimester combined screening test is performed from 11+0 to 13+6 weeks.
It confirms the viability of the baby, dates the pregnancy, giving an estimated date of delivery (an approximate due date) and also identifies multiple pregnancies.
It provides an opportunity to screen for chromosomal abnormalities (like Downs Syndrome) by measuring the nuchal translucency (fluid behind the baby’s neck). This measurement is combined with results of your blood tests (from the mother’s blood sample) to give a risk assessment for Down’s syndrome (Combined Screening).
You do not need to have a full bladder and you do not need to drink before the examination.