| Trend | Robson's Criteria | Jan'07-Sept'08 (Pre-COW) | Oct'08 – May'09 (Post-COW) | June'09- Sept'10 (Post-Propess) | Oct'10-Sept'11 (Rising trends) |
|---|---|---|---|---|---|
| Significant reduction | Multipara- SL | 7.48% | 5.62% | 6.48% | 3.92% P-0.12 |
| Significant reduction | Multipara- IOL | 19.5% | 14.8% | 19% | 16.8% P-0.11 |
| Variable reduction | Primipara- SL | 12.8% | 10.47% | 9.55% | 10.91% P-0.010 |
| Eventual rise | Primipara-IOL | 31.2% | 26 % | 21.6% | 34.2% P-0.00030 |
| Significant rise | Multipara-previous CS | 55.2% | 53.5% | 53.26% | 62.3% P-0.74 |