Implementing NIPT as part of a national prenatal screening program: The Dutch TRIDENT studies
Robert-Jan Galjaard1, Lidewij Henneman2, Merryn Macville3, Caroline Bax4, Mireille N. Bekker5, Christine de Die-Smulders3, Ilse Feenstra6, Mariette Hoffer7, Nicolette den Hollander7, Maarten F.C.M. Knapen8, Irene Van Langen9, Klaske Lichtenbelt10, Paola Lombardi11, Merel Van Maarle12, Karuna van der Meij13, Mijntje Pieters3, Heleen Schuring-Blom10, Esther Sikkel14, Servi Stevens3, Ron Suijkerbuijk15, Jeanine van der Ven, Diane Van Opstal, Janneke Weiss, Erik Sistermans, Dutch NIPT Consortium
1Department of Clinical Genetics, Erasmus MC Rotterdam, Rotterdam, Netherlands
2Dept. of Clinical Genetics, VU University Medical Center Amsterdam , Amsterdam, Netherlands
3Maastricht University Medical Center, Maastricht, Netherlands
4Dept. of Obstetrics, Amsterdam, Netherlands
5Division Woman and Baby, Department of Obstetrics, University Medical Center Utrecht, Utrecht, Netherlands
6Department of Human Genetics, Radboud University Medical Center, Nijmegen, Netherlands
7Leiden University Medical Center, Leiden, Netherlands
8Department of Obstetrics and Gynecology, Erasmus MC and Foundation Prenatal Screening Southwest region of the Netherlands, Rotterdam, Netherlands
9University Medical Center Groningen, University of Groningen, Groningen, Netherlands
10UMC Utrecht, Utrecht, Netherlands
11Department of Clinical Genetics, Amsterdam, Netherlands
12Academic Medical Center, Amsterdam, Netherlands
13VU University Medical Center, Amsterdam, Netherlands
14Radboud University Medical Centre , Nijmegen, Netherlands
15Department of Genetics, University Medical Centre Groningen, University of Groningen, 9700 RB, Groningen, Netherlands The Royal Dutch Organisation of Midwives (KNOV), Utrecht, Netherlands Erasmus Medical Center, Rotterdam, Netherlands Free University Medical Center, Amsterdam, Netherlands Netherlands, NL, Netherlands
Objectives
In most countries Non-Invasive Prenatal Testing (NIPT) has been introduced commercially without any governmental guidance. In the Netherlands, prenatal screening for fetal anomaly is subject to a governmental license. NIPT has been implemented as part of the TRIDENT studies (Trial by Dutch laboratories for Evaluation of NIPT). TRIDENT-2 aims at offering NIPT to all pregnant women (~174,000 women/year) within the national prenatal screening program. Since April 2017 women can choose NIPT as a contingent test after first-trimester combined testing (FCT), but may also choose NIPT as first-tier screening test. The TRIDENT studies evaluate implementation and women’s perspectives.
Methods
All pregnant women in the Netherlands are offered prenatal screening and are counselled by certified counselors, generally midwives. A first-tier NIPT costs women € 175, comparable to the costs of FCT (~€ 168). NIPT is performed by three Dutch university clinical genetic laboratories using an in-house validated test. Women can choose to have analysis of chromosomes 21, 18, and 13 without or with a report of incidental findings (findings other than trisomy 21, 13, 18) on the remaining autosomes, respectively using the ‘targeted’ or ‘whole genome’ WISECONDOR pipeline. Sex chromosomes are not analyzed.
Results
After eight months of study, 48,234 tests have been performed (nationwide uptake of prenatal screening by NIPT as first-tier test was 40%) and 98.3% reports successfully issued. Failure rate was less than 2%. Mean turnaround time was 7 working days. 80% of women chose to have all autosomes analyzed. A total of 152 cases of T21 (0,3%), 32 cases of T18 (0.1%), 41 cases of T13 (0.1%) and 158 (0.3%) other chromosomal aberrations were found. First year results (and available follow-up) will be presented at the meeting.
Conclusions
The Netherlands are the first country where NIPT is incorporated as a first-line test into a governmentally supported and health care funded prenatal aneuploidy screening program. The incorporation of the test in a university hospital laboratory and clinical service guarantees appropriate counselling and allows for proper follow-up. This 3-year study aims to provide all necessary information for a successful introduction of NIPT within the Dutch National prenatal screening program.
