Table II.

Characteristics of study sample

	Mean (SD)	n	%
Variables measured at birth
Monthly family income (minimum wage)
≤1		706	19.6
1.1-3		1772	49.3
3.1-6		707	19.7
6.1-10		218	6.1
>10		191	5.3
Maternal education (y)
0-4		1154	32.0
5-8		1557	43.2
9-11		394	10.9
≥12		501	13.9
Maternal skin color
White		2969	82.2
Non-white		641	17.8
Birthweight (g)
<2500		259	7.2
2500-2999		862	23.9
3000-3499		1356	37.5
≥3500		1133	31.4
Gestational age (wk)
≤36		164	5.6
37-38		645	22.1
≥39		2106	72.3
Birthweight for gestational age (z-score)
<−1.28 SD		413	14.2
−1.28-0 SD		1296	44.4
>0 SD		1205	41.4
Maternal smoking during pregnancy
Yes		1262	35.0
No		2342	65.0
Variables measured in childhood
Household assets index score (points)	0.34 (−0.55 to 0.68)*
Paternal education (y)
0-4		863	27.8
5-8		1415	45.6
9-11		405	13.1
≥12		419	13.5
Breastfeeding duration (mo)
<1		736	21.1
1-2.9		895	25.6
3-5.9		808	23.1
≥6		1054	30.2
Height-for-age z-score at 2 years
≤−2		424	12.8
−1.99 to −1		821	24.8
−0.99 to 1		1818	55.1
>1		242	7.3
Weight-for-age z-score at 2 years
≤−2		88	2.7
−1.99 to −1		356	10.8
−0.99 to 1		2225	67.3
>1		637	19.3
Height-for-age z-score at 4 years
≤−2		338	10.4
−1.99 to −1		842	26.0
−0.99 to 1		1842	56.9
>1		216	6.7
Weight-for-age z-score at 4 years
≤−2		65	2.0
−1.99 to −1		431	13.3
−0.99 to 1		2252	69.6
>1		488	15.1
Variables measured at 30 years
IQ	98.0 (12.6)
Educational attainment (y)	11.4 (4.1)
Monthly income (R$)	1000 (530-1890)*

^*Median and interquartile range.