N	DQ	P
Prenatal factors
Fecundation in vitro	yes	7	46 ± 12.1	0.124
	no	135	52.5 ± 10.8
Drug exposure in pregnancy*	yes	14	51.2 ± 11.3	0.734
	no	128	52.3 ± 11.5
Tobacco smoke exposure in pregnancy	yes	42	50.0 ± 11.4	0.127
	no	100	53.1 ± 10.8
Multiple gestation	yes	12	44.1 ± 11.2	0.012
	no	130	52.9 ± 11.4
Prematurity	yes	43	46.8 ± 11.6	<0.001
	no	99	54.5 ± 11.0
Post-term birth	yes	11	50.1 ± 12.3	0.517
	no	131	52.4 ± 11.2
IUGR	yes	32	42.8 ± 11.1	<0.001
	no	110	54.9 ± 11.4
Hypertensive disease of pregnancy †	yes	9	44.2 ± 10.9	0.030
	no	133	52.7 ± 11.3
Hemorrhagic complications of pregnancy ‡	yes	13	48.3 ± 11.6	0.180
	no	129	52.6 ± 10.9
Perinatal factors
Cesarean section	yes	55	51.3 ± 11.3	0.445
	no	87	52.8 ± 11.4
Birth asphyxia	yes	18	45.8 ± 12.0	0.012
	no	124	53.1 ± 11.3
Neonatal hypoxia §	yes	40	48.4 ± 11.5	0.014
	no	102	53.7 ± 11.4
Neonatal infection	yes	9	46.3 ± 12.2	0.109
	no	133	52.6 ± 11.3