|
Non-participants
|
12 month-old infants
|
18–24 month-old infants
|
---|
|
n = 355
|
n = 255
|
n = 150
|
---|
Mother
|
Age at delivery (years)
|
26.7 ± 5.5
|
27.1 ± 5.6
|
27.5 ± 5.1
|
Education (total years)
|
11.8 ± 2.8
|
11.9 ± 2.8
|
11.6 ± 2.8
|
Pre-pregnancy BMI (kg/m2)
|
24.9 ± 4.1
|
25.8 ± 4.4*
|
24.7 ± 3.9
|
2nd trimester blood lead (μg/dL)a
|
3.6 ± 2.5
|
3.5 ± 2.5
|
3.9 ± 2.8
|
3rd trimester blood lead (μg/dL)b
|
3.8 ± 2.7
|
3.7 ± 2.9
|
4.2 ± 3.4
|
Tibia lead (μg/g)c
|
4.7 ± 5.4
|
5.6 ± 5.8
|
4.9 ± 5.0
|
Infant
|
Sex (male) n (%)
|
182 (51)
|
129 (51)
|
90 (60)
|
Ever breastfed n (%)d
|
303 (85)
|
224 (88)
|
139 (93)
|
Gestational Age, weeks
|
38.3 ± 1.9
|
38.3 ± 1.5
|
38.5 ± 1.6
|
Birth Weight, kg
|
3.0 ± 0.5
|
3.1 ± 0.4
|
3.2 ± 0.4*
|
- For all analyses the imputed values for missing blood and tibia lead were used
-
anon-participant n = 354, 18–24 month-old infants n = 149
-
bnon-participant n = 301, 12 month-old infants n = 229, 18–24 month-old infants n = 139
-
cnon-participant n = 270, 12 month-old infants n = 199, 18–24 month-old infants n = 117
-
dnon-participant n = 329, 12 month-old infants n=, 18–24 month-old infants n = 145
- *Unless noted p > 0.05 for all comparison tests of covariates between non-participants and each age group