Table 3. Results of multiple logistic regression analysis.

Variable	OR	(99% CI)	p
Factors influencing cognitive development*
Severe brain injury (IVH III/PVH/PVL)	7.36	[2.52; 21.51]	0.000
Lower maternal educational attainment	3.83	[1.68; 8.77]	0.000
Birth weight <750g	2.50	[1.11; 5.63]	0.004
Mechanical ventilation >2 weeks	1.96	[0.91; 4.24]	0.024
Surgery for necrotizing enterocolitis	1.58	[0.22; 11.23]	0.546
Sex, male	1.43	[0.70; 2.91]	0.197
Sepsis	1.27	[0.61; 2.63]	0.396
<26 weeks’ gestation	1.19	[0.52; 2.72]	0.587
Multiple births	1.14	[0.50; 2.59]	0.679
Patent ductus arteriosus	1.06	[0.49; 2.29]	0.853
Spontaneous delivery	0.83	[0.28; 2.47]	0.653
Migration background, at least 1 parent	0.65	[0.30; 1.44]	0.164
Factors influencing the development of cerebral palsy
Severe brain injury (IVH III/PVH/PVL)	38.28	[12.55; 116.80]	0.000
Mechanical ventilation >2 weeks	2.74	[0.89; 8.41]	0.021
Sex, male	1.81	[0.63; 5.20]	0.146
<26 weeks’ gestation	1.67	[0.48; 5.74]	0.287
Birth weight <750 g	1.37	[0.41; 4.60]	0.505
Sepsis	1.22	[0.43; 3.48]	0.624
Surgery for necrotizing enterocolitis	1.17	[0.11; 12.78]	0.867
Lower maternal educational attainment	1.14	[0.40; 3.22]	0.754
Multiple births	0.93	[0.27; 3.17]	0.877
Migration background, at least 1 parent	0.68	[0.20; 2.27]	0.404
Spontaneous delivery	0.67	[0.15; 3.01]	0.487
Patent ductus arteriosus	0.31	[0.09; 1.14]	0.021

*IQ <85 versus IQ = 85

IQ,intelligence quotient; IVH III, grade 3 intraventricular hemorrhage; 99% CI, 99% confidence interval; OR, odds ratio; PVH, periventricular hemorrhage; PVL, periventricular leukomalacia