Comparison of cerebral palsy prevalence rates in same sex and different sex twins in survivors where the co-twin has died
| Birth weight group | Same sex | Different sex | Same − different sex difference (95%CI); p value | ||||||
|---|---|---|---|---|---|---|---|---|---|
| No of cerebral palsy/no of responders | Cerebral palsy prevalence per 1000 infant survivors | No of cerebral palsy/no of responders | Cerebral palsy prevalence per 1000 infant survivors | ||||||
| <1000 g | 17/76 | 224 | 8/40 | 200 | 24 (−146 to + 170); 0.7 | ||||
| 1000–1499 g | 14/75 | 187 | 1/32 | 31 | 155 (15 to 266); 0.02 | ||||
| 1500–1999 g | 4/33 | 121 | 0/15 | 0 | 121 (−94 to +275); 0.2 | ||||
| ⩾2000 g | 0/91 | 0 | 0/48 | 0 | — | ||||
| Not stated | 0/7 | 0 | 0/4 | 0 | — | ||||
| Total | 35/282 | 124 | 9/139 | 65 | 59 (−3 to 114); 0.06 | ||||