Univariate analysis of perinatal and postnatal variables according to intelligence quotient (IQ) (above and below mean)
| Variable | IQ⩾89 | IQ <89 | p Value |
|---|---|---|---|
| *Values are mean (SD). | |||
| †Values are mean (interquartile range). | |||
| OFC, Occipitofrontal circumference; PROM, premature rupture of the membranes; APH, antepartum haemorrhage; PDA, patent ductus arteriosus; PVH, periventricular haemorrhage. | |||
| Gestation (weeks)* | 30.2 (1.7) | 29.3 (2.5) | 0.001 |
| Birthweight centile† | 50 (25–75) | 50 (25–75) | 0.68 |
| Birth OFC centile† | 50 (25–75) | 50 (25–75) | 0.91 |
| Maternal illness | 17/132 (13%) | 7/125 (6%) | 0.045 |
| Pregnancy hypertension | 20/132 (15%) | 18/126 (14%) | 0.84 |
| PROM | 40/132 (30%) | 44/126 (35%) | 0.43 |
| APH | 20/132 (15%) | 25/126 (20%) | 0.32 |
| Antenatal steroids | 45/132 (34%) | 41/126 (33%) | 0.79 |
| Caesarean section | 67/132 (51%) | 57/126 (45%) | 0.37 |
| Days ventilation† | 0 (0–4) | 1.5 (0–7) | 0.003 |
| Days added oxygen† | 1 (0–6) | 2 (0–18) | 0.011 |
| Sepsis | 57/132 (43%) | 62/124 (50%) | 0.27 |
| PDA | 8/132 (6%) | 30/124 (24%) | 0.000 |
| Pneumothorax | 6/132 (5%) | 12/124 (10%) | 0.108 |
| Hypoglycaemia | 18/132 (14%) | 15/124 (12%) | 0.71 |
| PVH | 20/132 (15%) | 26/124 (21%) | 0.19 |
| Parenchymal lesion | 3/132 (2%) | 15/124 (12%) | 0.002 |
| Height 7 years, centile† | 25 (9–50) | 25 (9–50) | 0.14 |
| OFC 7 years, centile† | 9 (2–50) | 9 (0.4–25) | 0.006 |
| Weight 7 years, centile† | 50 (25–75) | 25 (9–75) | 0.047 |