| Characteristic | Total (n = 7910) | NIPT positives (n = 183) |
| Maternal age (yrs) | 35 (16 - 47) | 36 (25 - 46) |
| 16 - 24 yrs (n, %) | 144 (1.82%) | 0 (0.00%) |
| 25 - 29 yrs (n, %) | 724 (9.15%) | 8 (4.37%) |
| 30 - 34 yrs (n, %) | 2123 (26.84%) | 45 (24.59%) |
| 35 - 40 yrs (n, %) | 4346 (54.94%) | 97 (53.01%) |
| >40 yrs (n, %) | 573 (7.24%) | 33 (18.03%) |
| Gestational age (wks) | 15 (10 - 31) | 13 (10 - 20) |
| First trimester (9 - 13 wks) | 3469 (43.86%) | 99 (54.10%) |
| Second trimester (14 - 27 wks) | 4434 (56.06%) | 84 (45.90%) |
| Third trimester (≥28 wks) | 7 (0.09%) | 0 (0.00%) |
| BMI | 22 (15.1 - 45.8) | 21 (15.6 - 34.5) |
| Underweight (<18.5 bmi) | 363 (4.59%) | 10 (5.46%) |
| Normal (18.5 - 22.9 bmi) | 3661 (46.28%) | 99 (54.10%) |
| Overweight (23 - 24.9 bmi) | 1315 (16.62%) | 26 (14.21%) |
| Obese Class I (25 - 29.9 bmi) | 1429 (18.07%) | 22 (12.02%) |
| Obese Class II (30 - 35 bmi) | 338 (4.27%) | 5 (2.73%) |
| Obese Class III (>35 bmi) | 53 (0.67%) | 0 (0.00%) |
| Unknown | 751 (9.49%) | 21 (11.48%) |
| Singleton pregnancy | 7792 (98.51%) | 179 (97.81%) |
| Twin pregnancy | 118 (1.49%) | 4 (2.19%) |
| Other high-risk factors | ||
| 1 risk factor | 7142 (90.29%) | 154 (84.15%) |
| Serum screening test High risk group | 2029 (28.41%) | 47 (30.52%) |
| Ultrasound abnormal findings | 238 (3.33%) | 26 (16.88%) |
| Advanced maternal age | 2928 (41.00%) | 43 (27.92%) |
| Family history of aneuploidy | 68 (0.95%) | 1 (0.65%) |
| Other | 1879 (26.31%) | 37 (24.03%) |
| More than 2 risk factors | 734 (9.28%) | 29 (15.85%) |
| Unknown | 34 (0.43%) | 0 (0.00%) |