Free β-hCG | PAPP-A | ||||
---|---|---|---|---|---|
Between-weeks' difference | Sample size | F-ratio | Significance level | F-ratio | Significance level |
Group 1 vs. Group 2 (10+0 to 11+6) | 949 | 9.221 | p = 0.002* | 0.191 | p = 0.294 |
Group 2 vs. Group 3 (11+0 to 12+6) | 2179 | 0.0372 | p = 0.847 | 7.445 | p = 0.006* |
Group 3 vs. Group 4 (12+0 to 13+6) | 1934 | 0.947 | p = 0.331 | 8.942 | p = 0.003* |
All | 2883 | 3.516 | p = 0.015* | 8.696 | p < 0.001* |