Table 4.

Comparison of the detection risk of pathogenic variations in NT thickness < 4.5 mm fetuses.

Groups	Pathogenic variations			χ2 a	p-value a	OR a(95%CI)	χ2 b	p-value b	OR b(95%CI)	χ2 c	p-value c	OR c(95%CI)	Cases
	Aneuploidy	P/LP CNVs	Total
A	2 (0.8)	3 (1.1)	5 (1.9)	Ref.			7.129	<0.05	0.3 (0.1 ~ 0.7)	16.690	<0.0001	0.2 (0.07 ~ 0.4)	262
B
2.5–2.9	5 (2.1)	11 (4.6)	16 (6.7)	7.129	<0.05	3.6 (1.3 ~ 10.2)	Ref.			2.138	>0.05	0.6 (0.4 ~ 1.2)	239
3.0–3.4	25 (5.3)	22 (4.7)	47 (10.0)	16.690	<0.0001	5.7 (2.2 ~ 14.5)	2.138	>0.05	1.5 (0.9 ~ 2.8)	Ref.			470
3.5–4.4	45 (9.7)	15 (3.2)	60 (13.0)	25.110	<0.0001	7.7 (3.0 ~ 19.4)	6.452	<0.05	2.1 (1.2 ~ 3.7)	2.045	>0.05	1.3 (0.9 ~ 2.0)	462
C
2.5–2.9	6 (14.3)	2 (4.8)	8 (19.0)	21.958	<0.0001	12.1 (3.7 ~ 39.1)	6.978	<0.05	3.3 (1.3 ~ 8.2)	3.292	>0.05	2.1 (0.9 ~ 4.8)	42
3.0–3.4	13 (20.6)	3 (4.8)	16 (25.4)	42.555	<0.0001	17.5 (6.1 ~ 50.1)	18.409	<0.0001	4.7 (2.2 ~ 10.1)	12.635	<0.0001	3.1 (1.6 ~ 5.8)	63
3.5–4.4	27 (25.0)	7 (6.5)	34 (31.5)	70.930	<0.0001	23.6 (8.9 ~ 62.5)	37.057	<0.0001	6.4 (3.3 ~ 12.3)	33.631	<0.0001	4.1 (2.5 ~ 6.8)	108
D
2.5–2.9	1 (8.3)	2 (16.7)	3 (25.0)	14.208	<0.0001	17.1 (3.5 ~ 83.0)	5.472	<0.05	4.6 (1.1 ~ 18.8)	2.832	>0.05	3.0 (0.8 ~ 11.5)	12
3.0–3.4	4 (16.0)	4 (16.0)	8 (32.0)	41.083	<0.0001	24.2 (7.1 ~ 82.0)	17.537	<0.0001	6.6 (2.5 ~ 17.5)	11.633	<0.0001	4.2 (1.7 ~ 10.3)	25
3.5–4.4	10 (31.3)	4 (12.5)	14 (43.8)	75.814	<0.0001	40.0 (12.9 ~ 123.4)	39.363	<0.0001	10.8 (4.5 ~ 25.7)	31.969	<0.0001	7.0 (3.3 ~ 15.0)	32

^aThe detection rate of chromosomal abnormalities in group A was used as a control.

^bThe detection rate of chromosomal abnormalities in the group B of NT 2.5–2.9 mm was used as a control.

^cThe detection rate of chromosomal abnormalities in the group B of NT 3.0–3.4 mm was used as a control.