Table 2.
Characteristics of the sample according to breastfeeding duration†
| BF duration | |||||||
|---|---|---|---|---|---|---|---|
| Never BF (n = 1874) | <1 week (n = 1083) | 1–6 weeks (n = 1303) | 6 weeks to 3 months (n = 873) | 3–6 months (n = 1301) | ≥6 months (n = 3379) | ||
| n, (%) | n, (%) | n, (%) | n, (%) | n, (%) | n, (%) | ||
| Maternal characteristics* | |||||||
| Mother's age | Under 20 years (n = 241) | 119 (49) | 44 (18) | 36 (15) | 11 (5) | 10 (4) | 21 (9) |
| 20–24 years (n = 1075) | 372 (35) | 164 (15) | 177 (16) | 101 (9) | 86 (8) | 175 (16) | |
| 25–29 years (n = 2611) | 521 (20) | 328 (13) | 400 (15) | 238 (9) | 328 (13) | 796 (30) | |
| 30–34 years (n = 3489) | 520 (15) | 337 (10) | 418 (12) | 293 (8) | 542 (16) | 1379 (40) | |
| 35 years or over (n = 2383) | 339 (14) | 208 (9) | 270 (11) | 227 (10) | 334 (14) | 1005 (42) | |
| Age left full‐time education | 16 years or under (n = 1342) | 517 (39) | 197 (15) | 175 (13) | 101 (8) | 131 (10) | 221 (16) |
| 17 or 18 years (n = 2641) | 715 (27) | 389 (15) | 419 (16) | 237 (9) | 285 (11) | 596 (23) | |
| Over 18 years (n = 5830) | 642 (11) | 497 (9) | 709 (12) | 535 (9) | 885 (15) | 2562 (44) | |
| SEC | Managerial and professional (n = 4366) | 453 (10) | 380 (9) | 550 (13) | 407 (9) | 718 (16) | 1858 (43) |
| Intermediate occupations (n = 2066) | 457 (22) | 279 (14) | 299 (14) | 184 (9) | 237 (11) | 610 (30) | |
| Routine and manual occupations (n = 2200) | 645 (29) | 304 (14) | 329 (15) | 179 (8) | 207 (9) | 536 (24) | |
| Never worked (n = 473) | 177 (37) | 43 (9) | 37 (8) | 29 (6) | 54 (11) | 133 (28) | |
| Not classified (n = 708) | 142 (20) | 77 (11) | 88 (12) | 74 (10) | 85 (12) | 242 (34) | |
| Smoking status (pre and during pregnancy) | Never smoked or gave up >1 year before pregnancy (n = 7553) | 1187 (16) | 767 (10) | 947 (13) | 660 (9) | 1067 (14) | 2925 (39) |
| Gave up during pregnancy or within before getting pregnant (n = 1234) | 294 (24) | 174 (14) | 188 (15) | 129 (10) | 156 (13) | 293 (24) | |
| Continued to smoke during pregnancy (n = 847) | 357 (42) | 120 (14) | 143 (17) | 66 (8) | 50 (6) | 111 (13) | |
| Missing (n = 179) | 36 (20) | 22 (12) | 25 (14) | 18 (10) | 28 (16) | 50 (28) | |
| Ethnicity | White (n = 7195) | 1289 (18) | 782 (11) | 1003 (14) | 638 (9) | 952 (13) | 2531 (35) |
| Mixed (n = 93) | 13 (14) | 3 (3) | 6 (6) | 10 (11) | 15 (16) | 46 (49) | |
| Asian or Asian British (n = 344) | 12 (3) | 16 (5) | 31 (9) | 37 (11) | 67 (19) | 181 (53) | |
| Black or Black British (n = 188) | 7 (4) | 0 (0) | 8 (4) | 11 (6) | 39 (21) | 123 (65) | |
| Chinese or other (n = 78) | 4 (5) | 3 (4) | 5 (6) | 7 (9) | 10 (13) | 49 (63) | |
| Missing (n = 1915) | 549 (29) | 279 (15) | 250 (13) | 170 (9) | 218 (11) | 449 (23) | |
| Deprivation (IMD) | 1 (most deprived) (n = 1839) | 536 (28) | 232 (13) | 214 (12) | 133 (7) | 176 (10) | 548 (30) |
| 2 (n = 1872) | 416 (22) | 228 (12) | 258 (14) | 172 (9) | 237 (13) | 561 (30) | |
| 3 (n = 2025) | 391 (19) | 236 (12) | 289 (14) | 182 (9) | 252 (13) | 675 (33) | |
| 4 (n = 2041) | 299 (14) | 204 (10) | 277 (14) | 178 (9) | 320 (16) | 763 (37) | |
| 5 (least deprived) (n = 2029) | 232 (11) | 183 (9) | 263 (13) | 207 (10) | 315 (16) | 829 (41) | |
| Country | England (n = 4471) | 548 (12) | 375 (8) | 622 (14) | 420 (9) | 667 (15) | 1839 (41) |
| Scotland (n = 1931) | 404 (21) | 204 (11) | 211 (11) | 151 (8) | 250 (13) | 711 (37) | |
| Wales (n = 1678) | 389 (23) | 234 (14) | 237 (14) | 150 (9) | 191 (11) | 477 (28) | |
| Northern Ireland (n = 1733) | 533 (31) | 270 (16) | 233 (13) | 152 (9) | 193 (11) | 352 (20) | |
| Infant/birth characteristics | |||||||
| Gestational age (categories) | 37–39 weeks (n = 3827) | 804 (21) | 414 (11) | 543 (14) | 364 (10) | 478 (12) | 1224 (32) |
| 40–42 weeks (n = 5986) | 1070 (18) | 669 (11) | 760 (13) | 509 (9) | 823 (14) | 2155 (36) | |
| Birth weight | <2.5 kg (n = 177) | 38 (21) | 15 (8) | 27 (15) | 16 (9) | 23 (13) | 58 (33) |
| 2.5–2.99 kg (n = 1188) | 256 (22) | 122 (10) | 170 (14) | 107 (9) | 144 (12) | 389 (33) | |
| 3–3.49 kg (n = 3534) | 695 (20) | 378 (11) | 472 (13) | 316 (9) | 474 (13) | 1199 (34) | |
| 3.5 kg+ (n = 4853) | 882 (18) | 561 (12) | 629 (13) | 428 (9) | 650 (13) | 1703 (35) | |
| Birth order | First born (n = 4800) | 714 (15) | 586 (12) | 778 (16) | 452 (9) | 645 (13) | 1625 (34) |
| Not first born (n = 5013) | 1160 (23) | 497 (10) | 525 (10) | 421 (8) | 656 (13) | 1754 (35) | |
| Special care | Special care or lamp required (n = 669) | 103 (15) | 79 (12) | 115 (17) | 67 (10) | 77 (12) | 228 (34) |
| No special care or lamp (n = 9144) | 1771 (19) | 1004 (11) | 1188 (13) | 806 (9) | 1224 (13) | 3151 (34) | |
| Mode of delivery | Normal vaginal (n = 5863) | 1131 (19) | 602 (10) | 722 (12) | 500 (9) | 784 (13) | 2124 (36) |
| Delivery with ventouse (n = 618) | 94 (15) | 64 (10) | 86 (14) | 60 (10) | 91 (15) | 223 (36) | |
| Delivery with forceps (n = 863) | 142 (16) | 116 (13) | 125 (14) | 82 (10) | 122 (14) | 276 (32) | |
| Caesarean (n = 2456) | 506 (21) | 299 (12) | 369 (15) | 231 (9) | 301 (12) | 750 (31) | |
| Childcare setting (stage 2) | None (n = 9423) | 1788 (19) | 1039 (11) | 1244 (13) | 826 (9) | 1239 (13) | 3287 (35) |
| Crèche or nursery (n = 53) | 10 (19) | 4 (8) | 9 (17) | 6 (11) | 8 (15) | 16 (30) | |
| Nanny or childminder (n = 46) | 8 (17) | 2 (4) | 5 (11) | 9 (20) | 11 (24) | 11 (24) | |
| Friend or relative (n = 282) | 68 (24) | 38 (13) | 45 (16) | 28 (10) | 41 (15) | 62 (22) | |
SEC, Socio‐economic classification. IMD, Index of Multiple Deprivation. BF, breastfeeding.
*
Additional variables considered as potential confounders: smoking status post birth; skin‐to‐skin contact post birth.
†
Missing values shown only where total missing values is greater than 1%.