TRIDENT study: Trial by Dutch laboratories for Evaluation of Non-Invasive Prenatal Testing (NIPT)

TRIDENT study: Trial by Dutch laboratories for Evaluation of Non-Invasive Prenatal Testing (NIPT)


Starting date: 01/04/2014


Non-Invasive Prenatal Testing (NIPT) analyses circulating fragments of fetal DNA (cfDNA) in maternal plasma, obtained by a blood sample of the pregnant woman. NIPT can now be used to test for trisomy 21 (Down syndrome), 18 and 13 in the foetus.

NIPT in the Netherlands
In the Netherlands, NIPT is only available within the TRIDENT studies (Trial by Dutch laboratories for Evaluation of Non-Invasive Prenatal Testing). The TRIDENT studies have been designed and are carried out by the Dutch National NIPT consortium ( NIPT is performed in three clinical genetics laboratories (in-house validated tests). 

Eight regional Centres for Prenatal Screening and a national coordinating screening organisation (RIVM-CvB) organise the nationwide training of health professionals to update their knowledge and counselling skills. Uniform education materials for pregnant women have been developed in different languages. Depending on the outcome of the studies, NIPT will be fully implemented in health care (

TRIDENT studies

TRIDENT-1 includes women who are at an elevated risk of carrying a fetus with Down syndrome (or trisomy 18 or 13) based on the first trimester combined test (FCT) with a cut-off of 1:200. In addition, women with a previous child with a trisomy 13, 18 or 21 or carriers of Robertsonian translocations involving chromosome 21 or 13, can have direct access to NIPT. A license for the TRIDENT-1 study for high-risk women was first granted for two years (starting April 1, 2014) by the Ministry of Health, according to the rules of the Population Screening Act, and after positive advice had been given by the Health Council of the Netherlands (see report). The license was extended for another four years till April 2020. 

Since April 1st 2017 NIPT is available for every pregnant woman in the Netherlands within the TRIDENT-2 study. The TRIDENT-2 study was first granted for 3 years (2017-2020) after positive advice by the Health Council (see report), and later extended to April 2023. Women are still able to choose for NIPT as a contingent screening test after FCT, but now also have the option to have NIPT as their first screening test. Women pay 175 euro for a first-tier NIPT, which is almost similar to the costs for the FCT (~176 euros). The NIPT is subsidised by the Dutch government.

See also study Objectives, Staff, and Publications