Table 1.

Participant characteristics for mother-child pairs in original cohort, for mother-child pairs with at least one IBQ scale, and for mother-child pairs with at least one TBAQ scale.

Participant Characteristics	Original Cohort (N=404)		Some IBQ data (N=204)		Some TBAQ data (N=279)
	N	%	N	%	N	%
Alcohol use ab
No	337	83.4	165	80.9	234	83.9
Yes	59	14.6	33	16.2	38	13.6
Marital status a
Married/cohabiting	215	53.2	116	56.9	144	51.6
Other	189	46.8	88	43.1	135	48.4
Maternal race
White	86	21.3	58	28.4	64	22.9
Black	112	27.7	53	26	73	26.2
Hispanic/other	206	51	93	45.6	142	50.9
Breastfeeding c
No	119	29.5	58	28.4	106	38
Yes	213	52.7	146	71.6	173	62
Maternal education d
High school	201	49.8	85	41.7	134	48
Some college	103	25.5	50	24.5	69	24.7
College graduate	98	24.3	69	33.8	76	27.2
Child’s sex
Male	220	54.5	109	53.4	151	54.1
Female	184	45.5	95	46.6	128	45.9
Maternal age
<20 years	142	35.1	58	28.4	94	33.7
20–<30 years	176	43.6	87	42.6	120	43
30+ years	86	21.3	59	28.9	65	23.3
Smoking a
No	337	83.4	170	83.3	234	83.9
Yes	67	16.6	34	16.7	45	16.1

Abbreviations: IBQ, Infant Behavior Questionnaire; TBAQ, Toddler Behavior Assessment Questionnaire

^aDuring pregnancy

^b8 missing from original cohort, 6 missing from 12-month data, 7 missing from 24-month data

^c72 missing from original cohort

^d2 missing from original cohort