Table 2 Trends in the incidence of chromosomal abnormalities among all mothers and mothers aged 35 years and older over time
Time | General population | Mothers over 35 years population | RR (95% CI) | ||||
|---|---|---|---|---|---|---|---|
No. of births | No. of abnormal cases | Per 10,000 births | No. of births | No. of abnormal cases | Per 10,000 births | ||
2011 | 221,469 | 89 | 4.02 | 19,557 | 30 | 15.34 | 3.82(2.53 ~ 5.78) |
2012 | 253,540 | 136 | 5.36 | 22,397 | 37 | 16.52 | 3.08(2.14 ~ 4.44) |
2013 | 266,036 | 164 | 6.16 | 29,309 | 63 | 27.47 | 4.47(3.34 ~ 5.97) |
2014 | 265,289 | 181 | 6.82 | 23,635 | 67 | 28.35 | 4.16(3.15 ~ 5.51) |
2015 | 264,017 | 241 | 9.13 | 26,608 | 90 | 33.82 | 3.72(2.92 ~ 4.73) |
Total | 1,270,351 | 811 | 6.38 | 115,127 | 287 | 24.93 | 3.91(3.42 ~ 4.48) |