Table 2.
Frequency of chromosomal abnormalities in different groups of patients based on the levels of free βHCG MoM (RR, relative risk).
| free βHCG MoM | P value | ||||
|---|---|---|---|---|---|
| < 0.2 | 0.2–5 | > 5 | |||
| Trisomy 21 | Count | 7 | 222 | 24 | P < 0.001 |
| % within free βHCG MoM categories | 6.8% | 71.6% | 82.8% | ||
| RR | 0.09 | 1 | 1.16 | ||
| Trisomy 18 | Count | 58 | 35 | 0 | P < 0.001 |
| % within free βHCG MoM categories | 56.4% | 11.3% | 0.0% | ||
| RR | 4.99 | 1 | 0 | ||
| Trisomy 13 | Count | 26 | 19 | 0 | P < 0.001 |
| % within free βHCG MoM categories | 25.2% | 6.1% | 0.0% | ||
| RR | 4.13 | 1 | 0 | ||
| Turner Syndrome | Count | 5 | 17 | 0 | P > 0.05 |
| % within free βHCG MoM categories | 4.9% | 5.5% | 0.0% | ||
| RR | 0.89 | 1 | 0 | ||
| Klinefelter Syndrome | Count | 1 | 4 | 0 | P > 0.05 |
| % within free βHCG MoM categories | 0.9% | 1.3% | 0.0% | ||
| RR | 0.69 | 1 | 0 | ||
| Other chromosomal abnormalities | Count | 6 | 13 | 5 | P > 0.05 |
| % within free βHCG MoM categories | 5.8% | 4.2% | 17.2% | ||
| RR | 1.38 | 1 | 4.09 | ||
| Total | Count | 103 | 310 | 29 | – |
| % within free βHCG MoM categories | 100.0% | 100.0% | 100.0% | ||