Table 1.

Screening performance of NT alone (measured between 11 and 13 weeks gestation), based on 104 Down's syndrome and 22,284 unaffected pregnancies according to method

	DR (%) for FPR of				FPR (%) for DR of
Method	1%	3%	5%	10%	50%	60%	70%	80%	90%
Mixture model method1	41	57	62	68	1.9	4.3	12	28	43
Standard MoM method*	42	56	63	68	1.7	4.1	10	20	41

NT, nuchal translucency; DR, detection rate; FPR, false-positive rate; MoM, multiple of the median

*Derived from the mixture model distributions¹