Antenatal and peripartum risk factors for cerebral palsy by gestational age group and stratified for mode of delivery
| ⩽32 weeks | 33–36 wks | ⩾37 weeks | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cases | Controls | Unadjusted OR* (95% CI) | Adjusted OR (95% CI) | Cases | Controls | Unadjusted OR* (95% CI) | Adjusted OR (95% CI) | Cases | Controls | Unadjusted OR* (95% CI) | Adjusted OR (95% CI) | |
| Values are number (%). | ||||||||||||
| *Adjusted for source of data only. | ||||||||||||
| †When 0 in cell, unadjusted OR calculated after adding 0.5 to each cell.15 | ||||||||||||
| ‡Adjusted for source of data and for the other variables in the table. | ||||||||||||
| – Indicates that OR cannot be calculated. | ||||||||||||
| SGA, Small for gestational age; CS, caesarean section. | ||||||||||||
| Spontaneous onset of labour | 55 | 168 | 15 | 41 | 68 | 208 | ||||||
| No pre-eclampsia | 55 (100) | 167 (100) | – | – | 13 (100) | 36 (90) | 1 | 67 (98) | 205 (99) | 1 | 1 | |
| Pre-eclampsia | 0 (0) | 0 (0) | 0 (0) | 4 (10) | 0.3 (<0.1 to 5.9) | – | 1 (2) | 3 (1) | 1.1 (0.1 to 11.1) | 1.9‡ (0.2 to 22.0) | ||
| No SGA | 53 (96) | 129 (78) | 1 | 1 | 15 (100) | 28 (68) | 1 | 54 (82) | 175 (85) | 1 | 1 | |
| SGA | 2 (4) | 37 (22) | 0.1 (<0.1 to 0.6) | 0.2‡ (<0.2 to 0.7) | 0 (0) | 13 (32) | <0.1 (<0.1 to 1.2) | – | 12 (18) | 31 (15) | 1.2 (0.6 to 2.5) | 1.2‡ (0.6 to 2.7) |
| No clinical evidence of infection | 26 (48) | 120 (74) | 1 | 1 | 6 (50) | 34 (87) | 1 | 1 | 58 (89) | 192 (98) | 1 | 1 |
| Clinical evidence of infection | 28 (52) | 42 (26) | 2.8 (1.5 to 5.5) | 2.5‡ (1.3 to 4.9) | 6 (50) | 5 (13) | 6.8 (1.6 to 29.6) | 6.3‡ (1.2 to 33.4) | 7 (11) | 3 (1) | 8.9 (2.1 to 35.1) | 14.1‡ (2.8 to 70.1) |
| Induction or elective CS | 17 | 118 | 21 | 29 | 58 | 82 | ||||||
| No pre-eclampsia | 10 (59) | 56 (48) | 1 | 1 | 13 (62) | 18 (62) | 1 | 1 | 42 (72) | 76 (93) | 1 | 1 |
| Maternal pre-eclampsia | 7 (41) | 62 (52) | 0.9 (0.3 to 2.7) | 1.2‡ (0.3 to 4.8) | 8 (38) | 11 (38) | 1.0 (0.3 to 3.2) | 0.9‡ (0.2 to 3.3) | 16 (28) | 6 (7) | 4.9 (1.8 to 13.6) | 4.5‡ (1.5 to 13.3) |
| No SGA | 13 (77) | 51 (44) | 1 | 1 | 6 (29) | 13 (45) | 1 | 1 | 35 (61) | 68 (83) | 1 | 1 |
| SGA | 4 (23) | 66 (56) | 0.3 (0.1 to 1.0) | 0.3‡ (0.1 to 1.3) | 15 (71) | 16 (55) | 2.0 (0.6 to 6.7) | 3.1‡ (0.8 to 12.6) | 22 (39) | 14 (17) | 3.1 (1.4 to 6.8) | 2.1‡ (0.9 to 5.1) |
| No clinical evidence of infection | 7 (44) | 83 (72) | 1 | 1 | 14 (78) | 24 (86) | 1 | 1 | 48 (92) | 82 (100) | 1 | |
| Clinical evidence of infection | 9 (56) | 33 (28) | 4.0 (1.3 to 12.5) | 3.6‡ (1.1 to 11.6) | 4 (22) | 4 (14) | 1.7 (0.4 to 8.0) | 1.5‡ (0.3 to 7.4) | 4 (8) | 0 (0) | 15.3 (0.8 to 287.1)† | – |