Maternal age-specific cerebral palsy (CP) rates in singletons by quinquennium, and rate ratios (RR)
| Singletons | ||||
|---|---|---|---|---|
| CP rate per 1000 neonatal survivors (n) | ||||
| 1991–1995 | 1996–2000 | All 1991–2000 | RR (95% CI)* | |
| Maternal age group (years) | ||||
| <20 | 3.19 (54) | 3.21 (55) | 3.20 (109) | 1.46 (1.16 to 1.83) |
| 20–24 | 2.52 (115) | 2.85 (95) | 2.66 (210) | 1.21 (1.01 to 1.46) |
| 25–29 | 2.07 (126) | 2.37 (112) | 2.20 (238) | 1 (ref) |
| 30–34 | 2.15 (85) | 2.29 (90) | 2.22 (175) | 1.01 (0.83 to 1.23) |
| ≥35 | 2.76 (39) | 2.55 (44) | 2.65 (83) | 1.20 (0.94 to 1.55) |
| Total | 2.36 (419) | 2.57 (397) | 2.46 (816) | |
The number of cases for 1996–2000 is one less than the total, due to a missing maternal age.
↵* Rates by maternal age categories for 1991–2000 are compared with the reference category, 25–29 years.