OBJECTIVE: Non-invasive prenatal testing (NIPT) using cell-free fetal DNA in 
maternal plasma has been developed for the detection of fetal aneuploidy. 
Clinical trials have shown high sensitivity and specificity for trisomy 21 (T21) 
in both high-risk and average-risk populations. Although its great potential for 
prenatal medicine is evident, more information regarding the consequences of 
implementing NIPT in a national programme for prenatal screening is required.
STUDY DESIGN: A decision-analytic model was developed to compare costs and 
outcomes of current clinical practice in The Netherlands using conventional 
screening only, with two alternatives: implementing NIPT as an optional 
secondary screening test for those pregnancies complicated by a high risk for 
T21, and implementing NIPT as primary screening test, replacing conventional 
screening. Probability estimates were derived from a systematic review of 
international literature. Costs were determined from a health-care perspective. 
Data were analysed to obtain outcomes, total costs, relative costs and 
incremental cost-effectiveness ratios (ICERs) for the different strategies. 
Sensitivity analysis was used to assess the impact of assumptions on model 
results.
RESULTS: Implementing NIPT as an optional secondary, or as primary screening 
test will increase T21 detection rate by 36% (from 46.8% to 63.5%) and 54% (from 
46.8% to 72.0%), simultaneously decreasing the average risk of procedure-related 
miscarriage by 44% (from 0.0168% to 0.0094% per pregnant woman) and 62% (from 
0.0168% to 0.0064% per pregnant woman), respectively. None of the strategies 
clearly dominated: current clinical practice is the least costly, whereas 
implementing NIPT will cause total costs of the programme to increase by 21% 
(from €257.09 to €311.74 per pregnant woman), leading to an ICER of k€94 per 
detected case of T21, when utilised as an optional secondary screening test and 
by 157% (from €257.09 to €660.94 per pregnant woman), leading to an ICER of 
k€460 per detected case of T21, when utilised as primary screening test. 
However, implementing NIPT as triage test did result in the lowest expected 
relative costs per case of T21 diagnosed (k€141).
CONCLUSION: NIPT should be implemented in national health care as an optional 
secondary screening test for those pregnancies complicated by a high risk for 
T21.