A Novel Graphic-Aided Algorithm (gNIPT) Improves the Accuracy of Noninvasive Prenatal Testing

Table 1

Demographic characteristics of 13537 Chinese women.

Maternal age (years)	No. of samples	Average (years)	Percentage (%)
16-20	150	19	1.10
21-25	2665	24	19.70
26-30	5480	28	40.47
31-35	3247	33	23.99
36-40	1888	37	13.95
≥41	107	42	0.79
Gestational age (weeks)	No. of samples	Average (weeks)	Percentage (%)
12-15	984	15	7.27
16-19	10566	18	78.05
20-23	1813	21	13.40
24-27	172	25	1.27
28-31	1	29	0.00
36-40	1	36	0.00