RIVM Report 2017-0043
In 2013, the so-called combined tests performed by the seven Dutch screening laboratories to detect Down syndrome were performed according to the quality requirements. In general, the laboratories met the national quality requirements and the requirements of the international UK-NEQAS quality programme. These are the findings of an assessment by RIVM. This meets the directive of the Dutch Ministry of Health, Welfare and Sport to ensure the quality of the combined test.
Since 1 January 2007, the screening for Down syndrome has been available to all pregnant women, as part of a national screening programme. The screening for Edwards' syndrome and Patau's syndrome was added to the programme later. The screening is based on the measurements of a particular hormone and protein level, combined with an ultrasound scan measuring nuchal translucency. In 2013, a total of 52,263 combined tests were performed. In that year, 29.9 percent of all pregnant women in the Netherlands took part in such a test. This is slightly more than in 2009-2012.
The laboratories perform all blood analyses. The risk calculation based on blood analysis can be performed by the laboratory, but some of the ultrasound centres in the Netherlands are also capable of performing these calculations. In 46 percent of the performed combined tests, the risk calculation for Down syndrome, Edwards' syndrome and Patau's syndrome took place in the laboratories. This evaluation is only based on the risk calculation as performed by the laboratories.
The age at which most tests were performed, varies from 31.8 to 33.5 years (median age). The number of pregnant women that have an increased risk of a child with Down syndrome varies slightly per laboratory (between 5.1 and 6.8 percent). These differences are caused, among other things, by the average age of participating pregnant women, which differs slightly per region.
To reference/ cite this report use: DOI 10.21945/RIVM-2017-0043