Amniocentesis and Next Generation Sequencing (NGS)-Based Noninvasive Prenatal DNA Testing (NIPT) for Prenatal Diagnosis of Fetal Chromosomal Disorders

Figures & data

Table 1 Basic Information of the Participants

Item	NIPT+ (N = 29)	NIPT- (N = 2238)	t	P
Age	25.58 ± 2.15	26.21 ± 2.26	1.37	0.08
BMI (kg/m^2)	25.60 ± 3.54	22.63 ± 3.50	10.16	<0.001
Age of menarche	13.70 ± 1.56	13.81 ± 1.52	0.60	0.28
Number of pregnancies	1.60 ± 1.25	1.59 ± 1.23	0.56	0.27
Odd-even check	0.77 ± 0.62	0.73 ± 0.63	0.74	0.23

Abbreviation: BMI, body mass index.

Table 2 Results of Prenatal NIPT (Case)

Groups of High Risk	n	T13	T21	T18	XO	Y+	X+	Positivity
Serologically high risk, borderline risk	1185	1	5	1	1	3	1	1.01%
Advanced age	635	1	5		2	1		1.42%
Ultrasonographic abnormality	386	1	2	1	1	2	1	2.07%
Adverse birth history	61	0	0	0	0	0	0
Total		3	12	2	4	6	2	1.28%

Table 3 Comparison of the NIPT Results and Karyotyping by Amniocentesis

Types of NIPT	Positivity in NIPT (n)	Chromosome Karyotyping	Results of Karyotyping (n)	Pregnant Outcome
Trisomy 21	12	47,XN,+21	11	vtp
		46,XY	1	Live birth
Trisomy 13	3	47,XY,+13	2	vtp
		47,XXY	1	vtp
Trisomy 18	2	47,XN,+18	2	vtp
45,XO	4	46,XX	3	Live birth
		47,XXX	1	vtp
47,XXX/XXY	6	47,XXY	3	vtp
		47,XXX	2	vtp
		46,XY	1	Live birth
47,XYY	2	47,XYY	2	vtp

Abbreviation: vtp, termination of pregnancy.

Table 4 Results of NIPT in 2267 Cases

Positive Results in Diagnosis	Cases of Positivity	Sensitivity (%)	Specificity (%)	False Positivity (%)	Positive Predictive Value (%)
Trisomy 21	12	100(11/11)	99.96(2256/2257)	0.04	91.67
Trisomy 13	3	100(2/2)	99.96(2265/2266)	0.04	66.67
Trisomy 18	2	100(2/2)	100(2265/2265)	0	100
Total	17	100(15/15)	99.91(2252/2254)	0.09	88.24