Many hospitals in the UK and other countries are now offering this as a standard screening tool for Down’s syndrome. By itself, a nuchal scan is able to detect around 65% of Down’s syndrome affected babies. To increase accuracy, it is usually combined with a blood test to look for levels of specific hormones. This pushes the predictive value to around 80%. There is still a false positive rate of around 5% from a nuchal scan and therefore around 1 in 20 of those babies found to have an abnormally thick nuchal fold will actually be normal.
Echogenic intracardiac foci (EIF) or ‘golf balls’ in the heart are seen in anything up to 4% of all second trimester scans. It is thought that the cause of this finding is presence of deposited calcium within the papillary muscles of the heart. These are the muscles that control the heart valves.
In the majority of cases, presence of an echogenic intracardiac focus in isolation will be innocent. However, its finding should and would normally trigger a careful search for any other soft marker. If none is found, and there is no other risk factor such as advanced maternal age or family history; no further action is necessary. Finding of another soft marker is an indication to offer a diagnostic test such as amniocentesis as the likelihood of a chromosomal disorder such as Down’s syndrome is significant.