Table 2. The results of prenatal diagnosis in the AMA women.

Group	N	Chromosome abnormalities			CNVsd					Polymorphism
		Number abnormalities	Structural abnormalities		P	LP	NS	LB	B
Simple AMA	3,748	38 (1.0)a	13 (0.3)c		3	6	25	3	2	72 (1.9)
AMA combined with other indications	476	107 (22.5)b,#	6 (1.3)*		1	0	5	1	2	4 (0.84)
Total	4,224	145 (3.4)	19 (0.4)		4	6	30	4	4	76 (1.80)

a, b, c: there were 6, 3, 1 cases of mosaic respectively. d: the rate of pathogenic and like pathogenic CNVs was 0.24% (10/4,224). While it for Simple AMA group and AMA combined with other indications group were 0.24% and 0.21%, respectively. ^#, compared with simple AMA women, P<0.001. *, compared with simple AMA women, P=0.026. CNVs, copy number variations; P, pathogenic; LP, like pathogenic; NS, no subclassification; LB, like benign; B, benign; AMA, advanced maternal age.