Table 1 Maternal characteristics and gestational age of blood sampling
Maternal age at NIPT (years) | Number | Percent (100%) |
|---|---|---|
 ≤ 24 | 1533 | 18.83 |
 25–29 | 3328 | 40.88 |
 30–34 | 2157 | 26.50 |
 35–40 | 1011 | 12.42 |
 ≥ 41 | 112 | 1.38 |
 Advanced maternal age (≥ 35 years old) | 1123 | 13.79 |
Gestational age at NIPT (weeks) | ||
 ≤ 8 | 0 | 0.00 |
 9–12 | 916 | 11.25 |
 13–16 | 4344 | 53.36 |
 17–20 | 1509 | 18.54 |
 21–24 | 810 | 9.95 |
 25–28 | 347 | 4.26 |
 ≥ 29 | 212 | 2.60 |
 Unknown | 3 | 0.04 |
Range (weeks) | 9–34 | / |