Fetal chromosomal karyotype | Cases, n | ≧40 | 35–39 | 30–34 | 25–29 | < 25 |
---|---|---|---|---|---|---|
Trisomy 21 | 143 | 26 | 31 | 37 | 36 | 13 |
Trisomy 18 | 33 | 9 | 5 | 3 | 14 | 2 |
XXX | 10 | 0 | 2 | 3 | 5 | 0 |
Trisomy 13 | 6 | 1 | 2 | 0 | 2 | 1 |
Monosomy X | 5 | 0 | 0 | 3 | 2 | 0 |
Sex chromosome mosaicism | 3 | 0 | 0 | 1 | 1 | 1 |
XYY | 2 | 0 | 2 | 0 | 0 | 0 |
XXY | 2 | 0 | 0 | 1 | 1 | 0 |
Total | 204 | 36 | 42 | 48 | 61 | 17 |