Table 1. Characteristics of non-sibling and sibling groups.

CONTINUOUS FACTORS	Non-sibling group (N = 7,898)		Sibling group (N = 1,392)
	Mean	SD	Mean	SD
Age (months)	118.5	7.3	118.4	8.8
CBCL total t-score	46.4	11.3	45.1	11.3
DICHOTOMOUS FACTORS	N (%)		N (%)
Sex (female)	3,708 (46.9)		688 (49.4)
High CBCL (≥60)	1,022 (12.9)		150 (10.8)
Unplanned pregnancy	3157 (40.0)		577 (41.5)
Early alcohol exposure	2,177 (27.6)		276 (19.8)
Early tobacco exposure	1,112(14.1)		158 (11.3)
Early marijuana exposure	513 (6.5)		66 (4.7)
Complicated pregnancy	3,238 (41.0)		524 (37.6)
Complicated birth	1,952 (24.7)		333 (23.9)
Preterm birth	637 (8.1)		100 (7.1)
Caesarian section	2,517 (31.9)		373 (26.8)