Table 1. Sample characteristics for the entire sample by birth order of children.
| Characteristics | Child without siblings (n = 519, 46.51%) | First-born child (n = 81, 7.26%) | Second-born child (n = 440, 39.43%) | Third-born or younger child (n = 76, 6.81%) |
|---|---|---|---|---|
| Age of child (years), M (SD) | 2.47 (1.44) | 3.40 (1.21) | 2.78 (1.53) | 2.82 (1.51) |
| Gender, n (%) | ||||
| Male | 272 (52.41) | 37 (45.68) | 248 (56.36) | 49 (64.47) |
| Female | 247 (47.59) | 44 (54.32) | 192 (43.64) | 27 (35.53) |
| ObOw status, n (%) | ||||
| Normal | 375 (72.25) | 64 (79.01) | 286 (65.00) | 46 (60.53) |
| ObOw | 144 (27.75) | 17 (20.99) | 154 (35.00) | 30 (39.47) |
| Birthweight, n (%)a | ||||
| Low birthweight | 29 (5.78) | 3 (3.90) | 22 (5.49) | 8 (12.50) |
| Normal birthweight | 462 (92.03) | 69 (89.61) | 358 (89.28) | 53 (82.81) |
| Macrosomia | 11 (2.19) | 5 (6.49) | 21 (5.24) | 3 (4.69) |
| Ethnic groups, n (%)b | ||||
| Han | 468 (90.52) | 70 (86.42) | 392 (89.29) | 60 (80.00) |
| Others | 49 (9.48) | 11 (13.58) | 47 (10.71) | 15 (20.00) |
| Breastfeeding duration(month), M (SD)c | 9.98 (6.80) | 10.42 (6.60) | 11.32 (6.81) | 10.84 (6.76) |
| Gestational age(month), M (SD)d | 9.30 (0.58) | 9.29 (0.51) | 9.28 (0.62) | 9.24 (0.56) |
| Maternal age (years), M(SD) | 24.63 (4.08) | 24.13 (3.58) | 30.50 (4.63) | 32.33 (4.58) |
| Child’s health status, n (%) | ||||
| Good | 229 (44.12) | 36 (44.44) | 226 (51.36) | 46 (60.53) |
| Fair | 172 (33.14) | 19 (23.46) | 106 (24.09) | 10 (13.16) |
| Bad | 118 (22.74) | 26 (32.10) | 108 (24.55) | 20 (26.32) |
| Having any ObOw sibling, n (%) | 27 (33.33) | 29 (6.59) | 13 (17.11) | |
| Mother's educational attainment, n (%)e | ||||
| No schooling | 35 (6.90) | 17 (20.99) | 101 (23.11) | 34 (44.74) |
| Primary school | 110 (21.70) | 16 (19.75) | 133 (30.43) | 21 (27.63) |
| Middle school | 291 (57.40) | 41 (50.62) | 184 (42.11) | 18 (23.68) |
| High school or above | 71 (14.00) | 7 (8.64) | 19 (4.35) | 3 (3.95) |
| Father's educational attainment, n (%)f | ||||
| No schooling | 24 (4.67) | 8 (9.88) | 53 (12.10) | 24 (31.58) |
| Primary school | 100 (19.46) | 19 (23.46) | 134 (30.59) | 19 (25.00) |
| Middle school | 295 (57.39) | 45 (55.56) | 203 (46.35) | 29 (38.16) |
| High school or above | 95 (18.48) | 9 (11.11) | 48 (10.96) | 4 (5.26) |
| Children carer, n(%) | ||||
| Parents | 301 (58.00) | 52 (64.20) | 326 (74.09) | 57 (75.00) |
| Grandparents | 213 (41.04) | 26 (32.10) | 106 (24.09) | 18 (23.68) |
| Others | 5 (0.96) | 3 (3.70) | 8 (1.82) | 1 (1.32) |
| Parental emotional support, n (%) | ||||
| Positive | 301 (58.00) | 43 (53.09) | 249 (56.59) | 30 (39.47) |
| Neutral | 197 (37.96) | 30 (37.04) | 169 (38.41) | 35 (46.05) |
| Negative | 21 (4.05) | 8 (9.88) | 22 (5.00) | 11 (14.47) |
| Family income per capita (1000RMB), M (SD)g | 6.67 (10.85) | 5.93 (6.81) | 7.18 (12.06) | 6.17 (7.98) |
Note
a: n = 1044 cause of the missing data
b: n = 1112 cause of the missing data
c: n = 1107 cause of the missing data
d: n = 1108 cause of the missing data
e: n = 1101 cause of the missing data
f: n = 1109 cause of the missing data
g: n = 1115 cause of the missing data. Abbreviation: ObOw, obesity or overweight