TABLE 1.
Comparisons of study-population characteristics by feeding at 4 mo postpartum in the Upstate KIDS Study (2008–2010)1
| Exclusive breastfeeding (n = 715) | Breastfeeding and formula feeding (n = 360) | Breastfeeding and solids (n = 419) | Breastfeeding, formula feeding, and solids (n = 486) | Exclusive formula feeding (n = 631) | Formula feeding and solids (n = 1659) | |
| Maternal characteristic, n (%) | ||||||
| Age, y | ||||||
| ≤28 | 197 (27.6) | 89 (24.7) | 136 (32.5) | 133 (27.4) | 224 (35.5) | 735 (44.3) |
| >28 and ≤33 | 271 (37.9) | 125 (34.7) | 161 (38.4) | 175 (36.0) | 203 (32.2) | 484 (29.2) |
| >33 | 247 (34.6) | 146 (40.6) | 122 (29.1) | 178 (36.6) | 204 (32.3) | 440 (26.5) |
| Race | ||||||
| Non-Hispanic white | 603 (84.3) | 286 (79.4) | 362 (86.4) | 382 (78.6) | 500 (79.2) | 1334 (80.4) |
| Other | 112 (15.7) | 74 (20.6) | 57 (13.6) | 104 (21.4) | 131 (20.8) | 325 (19.6) |
| BMI post pregnancy, kg/m2 | ||||||
| ≤24.9 | 363 (52.8) | 160 (48.2) | 195 (49.1) | 179 (39.4) | 213 (35.6) | 567 (35.9) |
| >24.9 and ≤29.9 | 201 (29.3) | 106 (31.9) | 124 (31.2) | 153 (33.7) | 173 (28.9) | 414 (26.2) |
| >29.9 | 123 (17.9) | 66 (19.9) | 78 (19.7) | 122 (26.9) | 213 (35.6) | 599 (37.9) |
| Missing | 28 | 28 | 22 | 32 | 32 | 79 |
| Education completed | ||||||
| High school or less | 65 (9.1) | 41 (11.4) | 36 (8.6) | 54 (11.1) | 140 (22.2) | 409 (24.7) |
| More than high school and college or less | 357 (49.9) | 179 (49.7) | 231 (55.1) | 271 (55.8) | 294 (46.6) | 922 (55.6) |
| More than college | 293 (41.0) | 140 (38.9) | 152 (36.3) | 161 (33.1) | 197 (31.2) | 328 (19.8) |
| Marital status | ||||||
| Married | 677 (97.0) | 321 (93.3) | 381 (93.4) | 436 (92.8) | 529 (86.4) | 1338 (83.3) |
| Not married | 21 (3.0) | 23 (6.7) | 27 (6.6) | 34 (7.2) | 83 (13.6) | 268 (16.7) |
| Missing | 17 | 16 | 11 | 16 | 19 | 53 |
| Private insurance status | ||||||
| Has | 598 (83.6) | 291 (80.8) | 349 (83.3) | 408 (84.0) | 459 (72.7) | 1136 (68.5) |
| Does not have | 117 (16.4) | 69 (19.2) | 70 (16.7) | 78 (16.1) | 172 (27.3) | 522 (31.5) |
| Missing | 0 | 0 | 0 | 0 | 0 | 1 |
| Parity | ||||||
| Nulliparous | 417 (59.4) | 198 (55.5) | 218 (52.4) | 230 (47.7) | 350 (55.8) | 892 (54.0) |
| Parous | 285 (40.6) | 159 (44.5) | 198 (47.6) | 252 (52.3) | 277 (44.2) | 760 (46.0) |
| Missing | 13 | 3 | 3 | 4 | 4 | 7 |
| Self-reported postpartum depression | ||||||
| Yes | 98 (14.0) | 52 (15.0) | 64 (15.8) | 86 (18.0) | 141 (22.9) | 407 (25.1) |
| Missing | 14 | 12 | 14 | 9 | 14 | 40 |
| Paternal characteristic, n (%) | ||||||
| Age, y | ||||||
| ≤30 | 203 (29.4) | 91 (26.3) | 138 (34.2) | 129 (27.7) | 208 (35.6) | 624 (41.2) |
| >30 and ≤35 | 285 (41.3) | 128 (37.0) | 156 (38.7) | 177 (38.1) | 196 (33.6) | 505 (33.4) |
| >35 | 202 (29.3) | 127 (36.7) | 109 (27.1) | 159 (34.2) | 180 (30.8) | 384 (25.4) |
| Missing | 25 | 14 | 16 | 21 | 47 | 146 |
| Education completed | ||||||
| High school or less | 110 (15.5) | 61 (17.0) | 87 (21.0) | 96 (19.9) | 205 (32.9) | 601 (36.7) |
| More than high school and college or less | 378 (53.2) | 204 (56.8) | 230 (55.4) | 274 (56.7) | 321 (51.4) | 862 (52.6) |
| More than college | 222 (31.3) | 94 (26.2) | 98 (23.6) | 113 (23.4) | 98 (15.7) | 177 (10.8) |
| Missing | 5 | 1 | 4 | 3 | 7 | 19 |
| Infant characteristic, n (%) | ||||||
| Preterm birth, yes | 60 (8.4) | 52 (14.4) | 38 (9.1) | 86 (17.7) | 137 (21.7) | 364 (21.9) |
| Plurality | ||||||
| Singleton | 646 (90.4) | 262 (72.8) | 393 (93.8) | 378 (77.8) | 440 (69.7) | 1235 (74.4) |
| Twin | 69 (9.7) | 98 (27.2) | 26 (6.2) | 108 (22.2) | 191 (30.3) | 424 (25.6) |
| Sex | ||||||
| M | 365 (51.1) | 177 (49.2) | 223 (53.2) | 252 (51.9) | 311 (49.3) | 879 (53.0) |
| F | 350 (49.0) | 183 (50.8) | 196 (46.8) | 234 (48.2) | 320 (50.7) | 780 (47.0) |
| Rapid infant weight gain during first 4 mo postpartum | ||||||
| Yes | 98 (14.6) | 79 (23.4) | 56 (14.4) | 110 (24.4) | 178 (32.1) | 500 (34.3) |
| Missing | 42 | 22 | 29 | 36 | 77 | 199 |
| Ages and stages questionnaire status at 4 mo postpartum | ||||||
| Pass | 630 (96.8) | 295 (93.4) | 343 (98.6) | 386 (96.0) | 547 (92.7) | 1379 (95.2) |
| Missing | 64 | 44 | 71 | 84 | 41 | 210 |
| Daycare initiation at 8 mo postpartum | ||||||
| Not started | 333 (57.6) | 131 (44.9) | 181 (52.5) | 164 (44.6) | 223 (51.3) | 538 (49.2) |
| Started at ≤4 mo of age | 157 (27.2) | 117 (40.1) | 116 (33.6) | 154 (41.9) | 158 (36.3) | 391 (35.7) |
| Started at >4 mo of age | 88 (15.2) | 44 (15.1) | 48 (13.9) | 50 (13.6) | 54 (12.4) | 165 (15.1) |
| Missing | 137 | 68 | 74 | 118 | 196 | 565 |
| Conceived with fertility treatment, yes | 210 (29.4) | 125 (34.7) | 138 (32.9) | 178 (36.6) | 195 (30.9) | 432 (26.0) |
1
The following covariates did not have missing values: maternal age, race, and education, and preterm birth status, plurality, sex, and conceived with fertility treatment. Upstate KIDS Study, Upstate New York Infant Development Screening Program.