Table 2.
Characteristics of mothers and children in four European cohorts: ALSPAC, EDEN, EuroPrevall, and Generation XXI
| ALSPAC at age 2 years (n 8884) | EDEN at age 2 years (n 1341) | EuroPrevall at age 3 years (n 245) | Generation XXI at age 4 years (n 4293) | |||||
|---|---|---|---|---|---|---|---|---|
| Variable | n | % | n | % | n | % | n | % |
| Maternal age | ||||||||
| <25 years | 1447 | 16·3 | 204 | 15·2 | 0 | 0·0 | 664 | 15·5 |
| 25–35 years | 6714 | 75·6 | 992 | 74·0 | 99 | 40·2 | 3065 | 71·4 |
| >35 years | 723 | 8·1 | 145 | 10·8 | 147 | 59·8 | 564 | 13·1 |
| Maternal education | ||||||||
| Low | 2123 | 23·9 | 321 | 23·9 | 117 | 47·8 | 1784 | 41·6 |
| Medium | 3186 | 35·9 | 237 | 17·7 | 48 | 19·6 | 1218 | 28·4 |
| High | 3575 | 40·2 | 783 | 58·4 | 80 | 32·7 | 1291 | 30·1 |
| Maternal smoking during pregnancy | ||||||||
| Non-smoker | 6721 | 75·7 | 1018 | 75·9 | 163 | 66·5 | 3282 | 76·4 |
| Ever smoker | 1692 | 19·0 | 323 | 24·1 | 82 | 33·5 | 1011 | 23·6 |
| Missing | 201 | 5·3 | – | – | – | – | – | – |
| Duration of being breast-fed | ||||||||
| Never | 2114 | 23·8 | 353 | 26·3 | 18 | 7·5 | 359 | 8·4 |
| <1 month | 911 | 10·3 | 85 | 6·3 | 27 | 10·8 | 302 | 7·0 |
| 1–3 months | 1103 | 12·4 | 281 | 21·0 | 23 | 9·6 | 522 | 12·2 |
| 3–6 months | 1504 | 16·9 | 340 | 25·4 | 66 | 27·1 | 775 | 18·1 |
| ≥6 months | 3252 | 36·6 | 282 | 21·0 | 110 | 45·0 | 2335 | 54·4 |
| Gender | ||||||||
| Boys | 4591 | 51·7 | 695 | 51·8 | 141 | 57·1 | 2213 | 51·6 |
| Girls | 4293 | 48·3 | 646 | 48·2 | 106 | 42·9 | 2080 | 48·4 |
ALSPAC, Avon Longitudinal Study of Parents and Children; EDEN, Etude des Déterminants pre et postnatals de la santé et du développement de l’Enfant.