Table 1.
Main characteristics of the three studies
| ALSPAC | SWS | IFS 2010 | |
|---|---|---|---|
| Years of birth of infants | 1991–1992 | 1998–2008 | 2010–2011 |
| Location | South west of England | Southampton | Across United Kingdom |
| Number of participants | 13,988 | 3,158 | 10,768 (second stage) |
| Number of participants with breastfeeding information | 10,256 | 2,873 | 7,875 |
| Number (%) who ever breastfed | 7,669 (75) | 2,347 (82) | 5,676 (72) |
| Number (%) of cohort still breastfeeding at the age of 8 weeks (10 weeks for IFS 2010) | 6,079 (59) | 1,500 (52) | 2,828 (36) |
| Recruitment | In pregnancy | Prior to pregnancy | After birth |
| Age of first solid feeding | N = 6,031 | N = 1,467 | N = 2,749 |
| <4 months | 4,092 (68%) | 289 (20%) | 577 (21%) |
| 4 months | 1,641 (27%) | 807 (55%) | 875 (32%) |
| ≥5 months | 298 (5%) | 371 (25%) | 1,297 (47%) |
| Breastfeeding duration | N = 6,079 | N = 1,500 | N = 2,828 |
| Two to three completed monthsa | 1,525 (25%) | 351 (23%) | 775 (27%) |
| Four to five completed months | 960 (16%) | 370 (25%) | 464 (16%) |
| Six or more months | 3,594 (59%) | 779 (52%) | 1,589 (56%) |
a
In IFS, bands are 10 weeks to 4 months, >4 to 5 months, and > 5 months.
Abbreviations: ALSPAC, Avon Longitudinal Study of Parents and Children; SWS, Southampton Womans Survey; IFS 2010, Infant Feeding Survey 2010.