Table 1.

Demographic and clinical characteristics of the pregnant women (n = 12,243) enrolled in a study that investigated the use of noninvasive prenatal testing (NIPT) for screening for fetal sex chromosome aneuploidies

Characteristic	n (%)
Chinese	12,243
Singleton pregnancy	12,243
Gestational age at NIPT 12–20 weeks	12,243
Routine prenatal screening results	3932(32.12)
High risk	716(5.85)
Intermediate risk	2903(23.71)
Low risk	313(2.56)
Others	8311(67.88)
IVF	610(4.98)
Maternal age, years
<35	7382(60.30)
≧35	4861(39.70)
Total NIPT screen-positive	169(1.38)

Abbreviation: IVF In vitro fertilization