Marker Scan Summary
What is a marker scan?
A marker scan is a detailed ultrasound scan done with the specific purpose of looking for features which can change the risk of
Chromosomal problems (usually Down syndrome, but also sometimes Edward’s and Patau syndromes). There are certain features on
scan which are more common in these conditions compared to normal pregnancies. The scan can act as a screening test which will
make the chances of Down syndrome more or less likely compared to the risk before the scan was done.
We are also now experimenting with looking at the nasal bone length and prenasal oedema for detecting Downs syndrome after
14 weeks of pregnancy. We have included a picture of this as a slide on this page taken from a recent meeting in Croatia –
The World Congress for Fetal Medicine, organised by Professor Nicholaides.