Table 1 Description of important characteristics of the study population
Characteristic | All (n = 576) | With data available in both child blood and outcomes at 7-years (n = 446) | With data available in both cord blood and 7-years outcomes (n = 371) | |||
|---|---|---|---|---|---|---|
n | Mean (SD) or n (%) | n | Mean (SD) or n (%) | n | Mean (SD) or n (%) | |
Child characteristics | ||||||
Sex | 576 | 446 | 371 | |||
Male | 279 (48.4%) | 217 (48.6%) | 170 (45.8%) | |||
Female | 297 (51.6%) | 229 (51.4%) | 201 (54.2%) | |||
Child age (years) | 576 | 7.7 (0.2) | 446 | 7.6 (0.2) | 371 | 7.7 (0.2) |
Birth weight (g) | 576 | 3117.9 (542.7) | 446 | 3128.7 (530.9) | 371 | 3141.5 (515.4) |
Maternal Characteristics | ||||||
Maternal age at delivery (years) | 576 | 31.9 (6.6) | 446 | 32.1 (6.5) | 371 | 31.7 (6.7) |
Parity | 576 | 446 | 371 | |||
Nulliparous | 200 (34.7%) | 150 (33.6%) | 131 (35.3%) | |||
Primipara | 191 (33.2%) | 151 (33.9%) | 121 (32.6%) | |||
Multiparous | 185 (32.1%) | 145 (32.5%) | 119 (32.1%) | |||
Breastfeeding duration (months) | 576 | 446 | 371 | |||
No breastfeeding | 90 (15.6%) | 67 (15.0%) | 60 (16.2%) | |||
≤ 6 months | 258 (44.8%) | 201 (45.1%) | 158 (42.6%) | |||
7 – 18 months | 119 (20.7%) | 99 (22.2%) | 81 (21.8%) | |||
≥ 18 months | 109 (18.9%) | 79 (17.7%) | 72 (19.4%) | |||
Maternal marital status | 576 | 446 | 371 | |||
Married or in a couple | 314 (56.0%) | 238 (55.1%) | 207 (57.7%) | |||
Single | 140 (25.0%) | 114 (26.4%) | 85 (10.2%) | |||
Living with own family | 106 (19.0%) | 80 (18.5%) | 69 (32.1%) | |||
Missing | 16 | 14 | 10 | |||
Maternal education | 576 | 446 | 371 | |||
None or elementary school | 26 (4.5%) | 21 (4.7%) | 17 (4.6%) | |||
Some high school | 275 (47.8%) | 213 (47.8%) | 172 (46.4%) | |||
High school diploma | 124 (21.5%) | 98 (22.0%) | 91 (24.5%) | |||
College/University studies | 151 (26.2%) | 114 (25.5%) | 91 (24.5%) | |||
Household income (euros) | 566 | 437 | 364 | |||
≤ 800 Euros | 55 (9.7%) | 44 (10.1%) | 33 (9.2%) | |||
800 – 2300 Euros | 295 (52.1%) | 233 (53.3%) | 181 (50.7%) | |||
> 2300 Euros | 216 (38.2%) | 160 (36.6%) | 143 (40.1%) | |||
Missing | 10 | 9 | 7 | |||
Maternal Raven score | 541 | 35.4 (12.2) | 420 | 35.3 (12.1) | 345 | 35.4 (12.4) |
Maternal smoking during pregnancy | 576 | 446 | 371 | |||
No | 558 (96.9%) | 434 (97.3%) | 359 (96.8%) | |||
Yes | 18 (3.1%) | 12 (2.7%) | 12 (3.2%) | |||
Alcohol during pregnancy | 547 | 425 | 361 | |||
Never | 535 (97.8%) | 416 (97.9%) | 351 (97.2%) | |||
Ever | 12 (2.2%) | 9 (2.1%) | 10 (2.8%) | |||
Missing | 29 | 21 | 10 | |||
Neurodevelopmental outcomes | ||||||
WISC-IV composite scores | ||||||
FSIQ | 569 | 87.1 (16.8) | 442 | 86.6 (16.6) | 369 | 87.1 (17.0) |
Verbal comprehension | 569 | 93.8 (16.2) | 442 | 93.3 (16.1) | 369 | 93.7 (16.0) |
Perceptive reasoning | 569 | 83.9 (19.1) | 442 | 83.4 (19.0) | 369 | 84.3 (19.5) |
Processing speed | 569 | 91.8 (15.2) | 442 | 91.7 (15.1) | 369 | 91.7 (15.0) |
Working memory | 569 | 92.1 (15.1) | 442 | 91.8 (15.0) | 369 | 91.5 (15.2) |
SDQ subscales | ||||||
Internalizing problems | 576 | 4.7 (3.3) | 452 | 4.4 (3.2) | 371 | 4.9 (3.3) |
Externalizing problems | 576 | 7.0 (4.0) | 452 | 7.0 (4.1) | 371 | 6.9 (4.0) |