Number of observations at target ages by dataset
| Number of observations | |||||||
|---|---|---|---|---|---|---|---|
| Target age (weeks) | Age range | Sex | Widdowson (1959) | CIGS (1984) | GDS (1987) | GMS (1999) | Tampere (2003) |
| 0 | Birth | M | 573 | 142 | 1589 | 484 | 929 |
| F | 519 | 122 | 1582 | 477 | 889 | ||
| 7 | 5–9 weeks | M | 452 | 135 | 1201 | 388 | 1202 |
| F | 410 | 116 | 1217 | 379 | 1145 | ||
| 13 | 2–4 months | M | 573 | 137 | 1357 | 392 | 1220 |
| F | 520 | 118 | 1365 | 389 | 1189 | ||
| 26 | 5–7 months | M | 570 | 135 | 1186 | 240 | 1192 |
| F | 516 | 117 | 1212 | 247 | 1174 | ||
| 39 | 8–10 months | M | 569 | 134 | 898 | 222 | 993 |
| F | 515 | 116 | 893 | 233 | 962 | ||
| 52 | 11–14 months | M | 501 | 131 | 1068 | 308 | 1161 |
| F | 476 | 116 | 1109 | 300 | 1134 | ||
| 78 | 15–21 months | M | – | 125 | 642 | 61 | 1132 |
| F | – | 116 | 670 | 66 | 1098 | ||
| 104 | 22–30 months | M | – | 124 | 122 | – | 1076 |
| F | – | 115 | 115 | – | 1068 | ||
CIGS, Cambridge Infant Growth Study; GDS, Growth and Development Study; GMS, Gateshead Millennium Study.