Distribution of cases of ⩾ stage 3 retinopathy of prematurity (ROP) by gestation and city
| 22 weeks | 23 weeks | 24 weeks | 25 weeks | 26 weeks | 27 weeks | 28 weeks | |
| City 1 | 1 | 1 | 5 | 3 | 3 | 1 | 1 |
| City 2 | 0 | 0 | 0 | 2 | 0 | 1 | 1 |
| City 3 | 0 | 0 | 0 | 0 | 0 | 1 | 0 |
| City 4 | 0 | 1 | 0 | 0 | 0 | 0 | 0 |
| City 5 | 0 | 0 | 0 | 3 | 1 | 0 | 0 |
| Total no with ROP stage 3 or greater | 1 | 2 | 5 | 8 | 4 | 3 | 2 |
| Total no of babies screened | 1 | 4 | 15 | 34 | 41 | 86 | 76 |
| % with severe ROP | 100.0 | 50.0 | 33.3 | 23.5 | 9.8 | 3.5 | 2.6 |
| 95% CI | 2.5 to 100.0 | 6.8 to 93.2 | 11.8 to 61.6 | 10.8 to 41.2 | 2.7 to 23.1 | 0.7 to 9.9 | 0.3 to 9.2 |