This is a combination of a blood test and an ultrasound scan. It looks for signs that your baby may have a chromosomal anomaly such as Trisomy 21 (Down Syndrome) or other rarer chromosomal anomalies.
The tests consists of a blood test measuring two markers in your blood, which can be done between 9-13+6 weeks (optimally between 9-10 weeks), and an ultrasound scan to measure the length of your baby and a fold at the back of baby’s neck at 11-13+6 weeks. These are combined with your age, weight, gestation, and family history to give you either a low chance or an increased chance result.
It is important to know that this is a screening tool. It can give you the likelihood that you might have a baby with a chromosomal anomaly – an increased chance result does not mean that your baby definitely has a condition, and a low chance result does not guarantee that they do not.
If your screening test comes back with an increased chance of chromosomal anomalies, you will be offered diagnostic testing.