Table 1 Sample characteristics of CHILD and START cohorts
| Â | CHILD | START | P-value |
|---|---|---|---|
(N = 342) | (N = 490) | ||
Maternal | |||
Mother's Age | Â | Â | Â |
 Mean (SD) | 32.7 (± 4.4) | 30.1 (± 3.9) |  < 0.001 |
 Missing | 4 (1.2%) | 0 (0%) |  |
Parity | Â | Â | Â |
 Mean (SD) | 0.72 (± 0.89) | 0.80 (± 0.81) | 0.191 |
 Missing | 0 (0%) | 13 (2.6%) |  |
Pre-pregnancy BMI | Â | Â | Â |
 Mean (SD) | 24.7 (± 5.2) | 23.7 (± 4.4) | 0.0236 |
 Missing | 131 (38.3%) | 2 (0.4%) |  |
Pre-pregnancy weight | Â | Â | Â |
 Mean (SD) | 68.8 (± 15.2) | 62.6 (± 11.8) |  < 0.001 |
 Missing | 126 (36.8%) | 0 (0%) |  |
Gestational weight gain | Â | Â | Â |
 Mean (SD) | 15.4 (± 6.2) | 14.3 (± 7.5) | 0.0413 |
 Missing | 120 (35.1%) | 9 (1.8%) |  |
Gestational diabetes mellitus | Â | Â | Â |
 No | 328 (95.9%) | 313 (63.9%) |  < 0.001 |
 Yes | 14 (4.1%) | 176 (35.9%) |  |
 Missing | 0 (0%) | 1 (0.2%) |  |
Gestational hypertension | Â | Â | Â |
 No | 326 (95.3%) | 479 (97.8%) | 0.0801 |
 Yes | 16 (4.7%) | 11 (2.2%) |  |
Pre-eclampsia | Â | Â | Â |
 No | 331 (96.8%) | 486 (99.2%) | 0.0217 |
 Yes | 11 (3.2%) | 4 (0.8%) |  |
Smoking history | Â | Â | Â |
 Never smoked | 241 (70.5%) | 487 (99.4%) |  < 0.001 |
 Quit before this pregnancy | 68 (19.9%) | 1 (0.2%) |  |
 Quit during this pregnancy | 17 (5.0%) | 1 (0.2%) |  |
 Currently smoking | 11 (3.2%) | 0 (0%) |  |
 Missing | 5 (1.5%) | 1 (0.2%) |  |
Smoking exposure (hr/week) | Â | Â | Â |
 Mean (SD) | 1.0 (± 7.8) | 0.33 (± 2.7) | 0.13 |
 Missing | 12 (3.5%) | 39 (8.0%) |  |
Years of education | Â | Â | Â |
 Mean (SD) | 17.0 (± 3.1) | 15.8 (± 2.4) |  < 0.001 |
 Missing | 9 (2.6%) | 0 (0%) |  |
Social disadvantage index | Â | Â | Â |
 Mean (SD) | 0.41 (± 0.95) | 1.8 (± 1.4) |  < 0.001 |
 Missing | 37 (10.8%) | 69 (14.1%) |  |
Plant-based diet | Â | Â | Â |
 Mean (SD) | − 0.48 (± 0.46) | 1.6 (± 1.1) |  < 0.001 |
 Missing | 21 (6.1%) | 16 (3.3%) |  |
Health-conscious diet | Â | Â | Â |
 Mean (SD) | 0.21 (± 0.81) | − 0.42 (± 0.79) |  < 0.001 |
 Missing | 21 (6.1%) | 16 (3.3%) |  |
Western diet | Â | Â | Â |
 Mean (SD) | − 0.16 (± 0.64) | − 0.51 (± 0.65) |  < 0.001 |
 Missing | 21 (6.1%) | 16 (3.3%) |  |
Newborn | |||
Gestational age (weeks) | Â | Â | Â |
 Mean (SD) | 39.6 (± 1.3) | 39.3 (± 1.1) |  < 0.001 |
Newborn sex | Â | Â | Â |
 Male | 187 (54.7%) | 234 (47.8%) | 0.0581 |
 Female | 155 (45.3%) | 256 (52.2%) |  |
Birth length (cm) | Â | Â | Â |
 Mean (SD) | 51.7 (± 2.5) | 51.5 (± 2.6) | 0.381 |
 Missing | 65 (19.0%) | 7 (1.4%) |  |
Birth weight (kg) | Â | Â | Â |
 Mean (SD) | 3.5 (± 0.48) | 3.3 (± 0.45) |  < 0.001 |
 Missing | 4 (1.2%) | 1 (0.2%) |  |
Newborn BMI (kg/m2) | Â | Â | Â |
 Mean (SD) | 13.1 (± 1.4) | 12.3 (± 1.4) |  < 0.001 |
 Missing | 66 (19.3%) | 7 (1.4%) |  |
Newborn ponderal index (kg/m3) | Â | Â | Â |
 Mean (SD) | 25.4 (± 3.1) | 24.0 (± 3.2) |  < 0.001 |
 Missing | 66 (19.3%) | 7 (1.4%) |  |