Table 3.

Multivariate linear regression model for ADHD behavior scores at age 2 years.

	Males		Females
	β	SE B	β	SE B
STEP 1: COVARIATES
Maternal age at conception	0.01	0.02	0.01	0.02
Mother did not complete secondary school	0.02	0.19	0.04	0.20
Father not present in family home	0.01	0.29	0.02	0.28
Family income < $AUD24,000	−0.01	0.20	0.07	0.21
MATERNAL INTAKE DURING PREGNANCY
Alcohol ≥ several times per week	0.02	0.40	−0.05	0.41
Smoking 11 + cigarettes per day	0.07*	0.28	0.05	0.27
Parity = 1	0.06	0.21	−0.02	0.23
Parity > 1	−0.09*	0.25	−0.07	0.26
Baby blues symptoms	0.09*	0.03	−0.03	0.03
Child's age at 2 year assessment	−0.08*	0.56	0.00	0.60
PDP score	0.35**	0.10	0.33**	0.11
R2 for Step 1	0.17**		0.15**
STEP 2: PREDICTORS
N stress events during pregnancy	0.07*	0.11	0.10**	0.12
ΔR2 for Step 2	0.01*		0.01**
Change in Fmodel	4.73*		7.50**

PDP, pervasive developmental problems (autistic traits) subscale. ADHD, attention deficit hyperactivity subscale. *p < 0.05; ** p < 0.01.