Table 3

Comparison of child and caregiver characteristics by gestational age at birth

	Full term: ≥37 weeks		Preterm: <37 weeks
Child characteristics	N	Per cent (%)	N	Per cent (%)	P value*
Sex
Male	114	61	56	50	0.09
Female	74	39	55	50
Race/Ethnicity
Non-Hispanic white	93	49	44	40	0.33
Non-Hispanic black	60	32	45	41
Non-Hispanic other (includes multiple races)	22	12	12	11
Hispanic	13	7	10	9
Anthropometric measurements at visit 1	Mean (SD)		Mean (SD)
Length, cm	80.5 (3.3)		78.2 (3.9)		<0.0001
Weight, kg	11.2 (1.3)		10.4 (1.6)		<0.0001
WHO BMI-for-age z-score†	0.86 (0.90)		0.56 (1.1)		0.009
WHO BMI-for-age z-score category†
Underweight (BMI z-score <−2)	0	0	2	2	0.23
Healthy weight (BMI z-score −2 to <1)	111	59	69	62
Possible overweight (BMI z-score 1 to <2)	58	31	28	25
Overweight and obesity (BMI z-score ≥2)	19	10	12	11
Caregiver characteristics	N	Per cent (%)	N	Per cent (%)	P value
Relationship to child
Biological mother	174	93	105	95	0.22
Biological father	12	6	3	3
Other‡	2	1	3	3
Race/Ethnicity
Non-Hispanic white	106	56	52	47	0.34
Non-Hispanic black	63	34	48	43
Non-Hispanic other (includes multiple races)	10	5	7	6
Hispanic	9	5	4	4
Marital status
Married	106	56	56	50	0.28
Living with partner	36	19	26	23
Single/Never married	33	18	25	23
Other	12	6	3	3
Education level
High school or less	38	20	32	29	0.10
Some college or Associate’s degree	62	33	41	37
Bachelor’s degree	44	23	23	21
Graduate degree	44	23	15	14
	Mean (SD)		Mean (SD)		P value
Caregiver age (years)	30.7 (5.9)		31.1 (6.5)		0.61
Caregiver BMI	30.2 (8.1)		31.2 (7.5)		0.32
Household characteristics	N	Per cent (%)	N	Per cent (%)	P value
Annual household income (US$)
<20 000	40	21	38	35	0.02
20 000 to <50 000	53	28	36	33
50 000 to <90 000	43	23	14	13
90 000 or more	51	27	22	20
Household food security§
High food security	139	74	67	60	0.007
Marginal food security	27	14	15	14
Low food security	14	7	23	21
Very low food security	8	4	6	5
	Mean (SD)		Mean (SD)		P value
Number of adults in household	2.0 (0.63)		2.0 (0.65)		0.71
Number of children in household	2.2 (1.4)		2.2 (1.4)		0.94

Information missing for caregiver marital status (n=2), household income (n=2).
Percentages are column percentages and may not total to 100% due to rounding.
*P values from χ² (categorical variables) and t-tests (continuous variables).
†BMI-for-age z-score cut points and category labels as recommended by WHO.67 Children’s age was adjusted for preterm birth if children were born at <37 completed weeks’ gestation.
‡Includes adoptive mother (n=3), grandmother (n=1), other, non-relative (n=1).
§Food security was assessed using the 18-item USDA scale.
BMI, body mass index.