Table 1 Background characteristics of the participants (n = 1897)
Parental and household characteristics | n (%)a | Adolescent characteristics | n (%)a |
|---|---|---|---|
Maternal age (years) at pregnancy | Â | Sex | Â |
 Mean (SD) | 24.6(4.4) |  Male | 1129(59.5) |
 Median (IQR) | 24(21–28) |  Female | 768(40.5) |
 Q1 (15 ~ 21) | 561(29.6) | Birthweight (gram)/Mean (SD) | 3211(415) |
 Q2 (22 ~ 24) | 504(26.6) | Gestational weeks at delivery/Mean (SD) | 39.8(1.6) |
 Q3 (25 ~ 28) | 428(22.6) | Birthweight-for-gestational-age and sex z score/Mean (SD) | -0.19(1.04) |
 Q4 (29 ~ 41) | 404(21.3) | Preterm (< 37 gestational weeks) | 75(4.0) |
Maternal education |  | Low birth weight (< 2500 g) | 60(3.3) |
 <3 years | 117(6.2) | Small-for-gestational age (< population 10th percentile) | 245(13.8) |
 Primary | 543(28.7) | Age (years) |  |
 Secondary | 975(51.5) |  Mean (SD) | 11.8(0.8) |
 High school and above | 257(13.6) |  Median (IQR) | 12(11–12) |
Maternal occupation | Â | HAZ/Mean (SD) | 0.1(1.1) |
 Farmer | 1609(85.3) | BAZ/Mean (SD) | -0.22(1.1) |
 Other | 278(14.7) | Overweight/obesity (BAZ ≥ 1 SD) | 273(14.6) |
Paternal age (years) at pregnancy | Â | Stunting (HAZ<-2 SD) | 44(2.3) |
 Mean (SD) | 27.9(4.1) | School type |  |
 Median (IQR) | 27(25–31) |  Village | 272(14.3) |
 Q1 (20 ~ 25) | 673(35.6) |  Township | 818(43.1) |
 Q2 (26 ~ 27) | 345(18.2) |  County | 807(42.5) |
 Q3 (28 ~ 31) | 478(25.3) | Household wealth at enrolment |  |
 Q4 (32 ~ 44) | 396(20.9) |  Low | 673(35.5) |
Paternal education |  |  Medium | 602(31.7) |
 <3 years | 27(1.4) |  High | 622(32.8) |
 Primary | 287(15.2) | Adolescent cognitive test scores/Mean (SD) |  |
 Secondary | 1123(59.3) |  Full-scale intelligence quotient | 97.4(12.1) |
 High school and above | 456(24.1) |  Verbal comprehension index | 102.1(15.4) |
Paternal occupation |  |  Working memory index | 94.0(10.9) |
 Farmer | 1441(76.1) |  Perceptual reasoning index | 95.9(12.0) |
 Other | 452(23.9) |  Processing speed index | 99.2(13.6) |
Parity at enrolment | Â | Scores of adolescent emotional and behavioural problems/Mean (SD) | Â |
 0 | 1237(65.2) |  Total problem score | 49.5(25.5) |
 ≥ 1 | 660(34.8) |  Internalizing problem score | 11.3(8.0) |
Maternal mid-upper-arm circumference (cm) at enrolment/Mean (SD) |  |  Externalizing problem score | 8.6(7.5) |
 <21.5 | 331(17.6) |  Anxiety/depression | 4.8(3.9) |
 ≥ 21.5 | 1547(82.4) |  Withdrawn | 3.4(2.7) |
Household wealth at enrolment |  |  Somatic complaints | 3.1(3.0) |
 Low | 629(33.2) |  Social problems | 4.0(3.3) |
 Medium | 692(36.5) |  Thought problems | 2.8(2.9) |
 High | 576(30.4) |  Attention problems | 4.4(2.9) |
Randomized regimen |  |  Rule breaking | 2.8(3.1) |
 Folic acid | 661(34.8) |  Aggressive behaviour | 5.9(4.9) |
 Folic acid plus iron | 610(32.2) |  |  |
 Multiple micronutrients | 626(33.0) |  |  |