Danish population study: numbers of babies born with Down syndrome reduced by 50% with implementation of national screening

In the same week that reporting of a small increase in the numbers of babies born with Down syndrome in the UK is being debated (click here for some examples of the arguments; and here for a deeper analysis by Frank Buckley; and here for Tom Shakespeare's succint view), a new study from Denmark found a very different phenomenon.

A research study of all pregnancies and births in Denmark over the period of implementation of national screening recommendation is reported in the British Medical Journal published online on 27th November 2008. The number of live births of babies with Down syndrome was halved during 2005 - 2006, compared to 2000 - 2004.

From the published report:

What is already known on this topic

• Many countries are currently trying to achieve national screening strategies for Down’s syndrome

• None has described how a combined screening strategy in the first trimester affects numbers of infants born with Down’s syndrome or rate of invasive procedures
• Detection rates and false positive rates for the combined first trimester risk assessment have been reported only from specialised centres or from regional experience

What this study adds

• After implementation of a national screening policy in Denmark, the number of infants born with Down’s syndrome and the rate of invasive procedures was noticeably reduced
• The screening strategy achieved high detection rates and low false positive rates

The full text of the report is available at BMJ Online, by clicking on the link below:
Impact of a new national screening policy for Down’s syndrome in Denmark: population based cohort study: BMJ 2008;337:a2547