Is ultrasound as useful as we think?

Aug 16, 2007

The usefulness of foetal 'nuchal thickness' as a technique for attempting to diagnose Down's syndrome in obstetric ultrasound is overstated and reliance on this surrogate marker may result in the 'loss' of normal babies.

In a recent article published in Ultrasound, the Journal of the British Medical Ultrasound Society (Vol. 15, Number 3, 2007), Dr Hylton Meire raises the possibility that ultrasound is not as useful as has been suggested. He particularly emphasises the lack of scientific data to support the use of foetal 'nuchal thickness' measurements in routine clinical ultrasound practice to ascertain the presence of Down's syndrome.

The routine use of ultrasound in obstetrics became commonplace in the years before clinicians tried to ensure that all changes in medical practice were supported by scientifically valid research studies.

The nuchal translucency thickness scan is an ultrasound scan performed between 11 and 13+6 weeks of pregnancy, during which the fluid at the back of the baby’s neck (the nuchal translucency) is measured. Babies with abnormalities tend to accumulate more fluid at the back of their neck during the first trimester, causing this clear space to be larger than average.

Dr Meire reviews the available scientific evidence in support of the routine use of ultrasound as a screening procedure for pregnant women. He concentrates on the ‘routine abnormality scan’, typically performed at 18-20 weeks of pregnancy, and assessment of the foetal ‘nuchal thickness’ performed at 11-13 weeks as a screening procedure for chromosome abnormalities such as Down’s syndrome.

Dr Meire concludes that there is no valid data showing any population benefit from the 18-20 week scan and shows that this position has been agreed by many of the world’s major medical bodies for many years. Several of these bodies have expressed the need for a large confirmatory study but accept that no such study has yet been performed.

Dr Meire also shows that the value of 'nuchal thickness' measurement has probably been overstated and the technique has not been subjected to valid scientific and statistical scrutiny. Using this technique to try to prevent the births of all cases of the two most common chromosome abnormalities in the UK would lead to the loss of 3200 normal babies every year*.

Source: British Medical Ultrasound Society

Explore further: New research demonstrates benefits of national and international device registries

add to favorites email to friend print save as pdf

Related Stories

Why the Sony hack isn't big news in Japan

6 hours ago

Japan's biggest newspaper, Yomiuri Shimbun, featured a story about Sony Corp. on its website Friday. It wasn't about hacking. It was about the company's struggling tablet business.

Hopes, fears, doubts surround Cuba's oil future

7 hours ago

One of the most prolific oil and gas basins on the planet sits just off Cuba's northwest coast, and the thaw in relations with the United States is giving rise to hopes that Cuba can now get in on the action.

Ancient clay seals may shed light on biblical era

7 hours ago

Impressions from ancient clay seals found at a small site in Israel east of Gaza are signs of government in an area thought to be entirely rural during the 10th century B.C., says Mississippi State University archaeologist ...

Off-world manufacturing is a go with space printer

9 hours ago

On Friday, the BBC reported on a NASA email exchange with a space station which involved astronauts on the International Space Station using their 3-D printer to make a wrench from instructions sent up in ...

Recommended for you

New approach to particle therapy dosimetry

Dec 19, 2014

Researchers at the National Physical Laboratory (NPL), in collaboration with EMRP partners, are working towards a universal approach to particle beam therapy dosimetry.

Supplement maker admits lying about ingredients

Dec 17, 2014

Federal prosecutors say the owner and president of a dietary supplement company has admitted his role in the sale of diluted and adulterated dietary ingredients and supplements sold by his company.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.