Table 1. Characteristics of the study groups.

	Very preterm (n = 183)	Term (n = 69)
Birth weight (g), M (SD)	969 (221)	3318 (510)
Birth weight SD score, M (SD)	-0.54 (0.95)	0.11 (0.90)
Gestational age (weeks), M (SD)	27.5 (1.93)	39.1 (1.30)
Female, n (%)	89 (47%)	35 (51%)
Singleton, n (%)	104(57%)	65 (94%)
Social risk at seven years, M (SD)	2.3 (1.8)	1.4 (1.4)
Oxygen at 36 weeks, n (%)	62 (34%)	-
IVH grade III/IV: n (%)	6 (3%)	-

Note. M = mean; SD = standard deviation; IVH=intraventricular haemorrhage on cranial ultrasound.