Table 1. The proportion of increased NT among number of amniocentesis each year and the rate of chromosomal aberrations.

NT: nuchal translucency.

Year	Number of amniocentesis	Percentage of amniocentesis (%)	Number of NT increased	Percentage of NT increased (%)	Number of chromosomal aberrations	Percentage of chromosomal aberrations (%)
2015	3192	17.3	480	15.0	85	17.7
2016	2903	15.7	129	4.4	25	19.4
2017	3091	16.7	476	15.4	90	18.9
2018	3182	17.2	550	17.3	117	21.3
2019	3301	17.8	601	18.2	119	19.8
2020	2830	15.3	484	17.1	124	25.6
Total	18499	100	2720	14.7	560	20.6