Table 1 Characteristics of the study subjects according to infants with and without food allergy or eczema in infancy
Variables | Total | Food allergy | No food allergy | P value | Eczema | No eczema | P value |
|---|---|---|---|---|---|---|---|
No. of subjects | 903 | 200 | 703 | Â | 226 | 677 | Â |
Parental characteristics | |||||||
 Maternal age (years) (n = 903) | 29.9 ± 3.8 | 30.0 ± 3.8 | 29.9 ± 3.9 | 0.642‡ | 29.9 ± 3.6 | 29.9 ± 3.9 | 0.791‡ |
 Pre-pregnancy BMI (kg/m2) (n = 883) | 21.2 ± 3.0 | 21.3 ± 2.9 | 21.2 ± 3.1 | 0.687‡ | 21.2 ± 3.0 | 21.2 ± 3.0 | 0.957‡ |
 Maternal education (>  12 years, %) (n = 903) | 760 (84.2) | 165 (82.5) | 595 (84.6) | 0.465†| 189 (83.6) | 571 (84.3) | 0.799†|
 Multiple pregnancy (%) (n = 903) | 23 (2.5) | 5 (2.5) | 18 (2.6) | 0.962†| 7 (3.1) | 16 (2.4) | 0.544†|
 Caesarean section (%) (n = 903) | 373 (41.3) | 91 (45.5) | 282 (40.1) | 0.172†| 95 (42.0) | 278 (41.1) | 0.797†|
 Maternal active or passive smoking during pregnancy (%) (n = 903) | 97 (10.7) | 23 (11.5) | 74 (10.5) | 0.695†| 28 (12.4) | 69 (10.2) | 0.356†|
 Exposure to antibiotics during pregnancy (%) (n = 903) | 15 (1.7) | 4 (2.0) | 11 (1.6) | 0.753§ | 8 (3.5) | 7 (1.0) | 0.017§ |
 Domestic pets kept at delivery (%) (n = 903) | 48 (5.3) | 12 (6.0) | 36 (5.1) | 0.625†| 13 (5.8) | 35 (5.2) | 0.735†|
 Post-partum depression at 1 month after childbirth (%) (n = 892) | 52 (5.8) | 16 (8.1) | 36 (5.2) | 0.125†| 14 (6.2) | 38 (5.7) | 0.771†|
 Family income per capita (>  5000 yuan / month, %) (n = 902) | 389 (43.1) | 91 (45.5) | 298 (42.5) | 0.442†| 92 (40.7) | 297 (43.9) | 0.396†|
 Parental history of allergy (%) (n = 903) | 272 (30.1) | 91 (45.5) | 181 (25.7) | <  0.001†| 94 (41.6) | 178(26.3) | <  0.001†|
Infantile characteristics | |||||||
 Sex (male, %) (n = 903) | 467 (51.7) | 106 (53.0) | 361 (51.4) | 0.681†| 115 (50.9) | 352 (52.0) | 0.773†|
 Birth weight (<  2500 g, %) (n = 900) | 26 (2.9) | 4 (2.0) | 22 (3.1) | 0.402†| 5 (2.2) | 21 (3.1) | 0.483†|
 Preterm birth (<  37 weeks of gestation, %) (n = 898) | 43 (4.8) | 8 (4.0) | 35 (5.0) | 0.565†| 11 (4.9) | 32 (4.8) | 0.949†|
 Season of birth (autumn-winter, %) (n = 903) | 428 (47.4) | 103 (51.5) | 325 (46.2) | 0.188†| 115 (50.9) | 313 (46.2) | 0.225†|
 No. of older siblings (≥ 1, %) (n = 903) | 255(28.2) | 45 (22.5) | 210 (29.9) | 0.041†| 54 (23.9) | 201 (29.7) | 0.094†|
 Exclusive breast feeding (≥ 6 months, %) (n = 903) | 125 (13.8) | 20 (10.0) | 105 (14.9) | 0.075†| 26 (11.5) | 99 (14.6) | 0.240†|
 Solid food introduced (<  6 months, %) (n = 903) | 720 (79.7) | 171 (85.5) | 549 (78.1) | 0.022†| 185 (81.9) | 535 (79.0) | 0.359†|
 Exposure to antibiotics through medication during the first year of life (%) (n = 903)¶ | 201 (22.3)a 184 (20.4)b | 43 (21.5) | 158 (22.5) | 0.770†| 26 (11.5) | 158 (23.3) | <  0.001†|
Maternal diet during pregnancy | |||||||
Milk or milk products consumption (%) (n = 903) |  |  |  | 0.335†|  |  | 0.047†|
 ≤ 2 times a week | 259 (28.6) | 56 (28.0) | 203 (28.9) |  | 51 (22.6) | 208 (30.8) |  |
 3–4 times a week | 257 (28.5) | 65 (32.5) | 192 (27.3) |  | 74 (32.7) | 183 (27.0) |  |
  ≥ 5 times a week | 387 (42.9) | 79 (39.5) | 308 (43.8) |  | 101 (44.7) | 286 (42.2) |  |
Eggs consumption (%) (n = 903) |  |  |  | 0.341†|  |  | 0.022†|
 ≤ 2 times a week | 188 (20.8) | 47 (23.5) | 141 (20.1) |  | 55 (24.3) | 133 (19.6) |  |
 3–4 times a week | 259 (28.7) | 50 (25.0) | 209 (29.7) |  | 49 (21.7) | 210 (31.0) |  |
 ≥ 5 times a week | 456 (50.5) | 103 (51.5) | 353 (50.2) |  | 122 (54.0) | 334 (49.3) |  |
Beans or bean products consumption (%) (n = 903) |  |  |  | 0.991†|  |  | 0.716†|
 < 1 time a week | 249 (27.6) | 55 (27.5) | 194 (27.6) |  | 60 (26.5) | 189 (27.9) |  |
 1–2 times a week | 302 (33.4) | 67 (33.5) | 235 (33.4) |  | 72 (31.9) | 230 (34.0) |  |
 3–4 times a week | 231 (25.6) | 50 (25.0) | 181 (25.7) |  | 59 (26.1) | 172 (25.4) |  |
 ≥ 5 times a week | 121 (13.4) | 28 (14.0) | 93 (13.2) |  | 35 (15.5) | 86 (12.7) |  |
Nuts consumption (%) (n = 903) |  |  |  | 0.497†|  |  | 0.383†|
 < 1 time a week | 217 (24.0) | 50 (25.0) | 167 (23.8) |  | 55 (24.3) | 162 (23.9) |  |
 1–2 times a week | 279 (30.9) | 54 (27.0) | 225 (32.0) |  | 61 (27.0) | 218 (32.2) |  |
 3–4 times a week | 191 (21.2) | 42 (21.0) | 149 (21.2) |  | 48 (21.2) | 143 (21.2) |  |
 ≥ 5 times a week | 216 (23.9) | 54 (27.0) | 162 (23.0) |  | 62 (27.4) | 154 (22.7) |  |
Aquatic products consumption (%) (n = 903) |  |  |  | 0.127†|  |  | 0.249†|
 < 1 time a week | 259 (28.7) | 47 (23.5) | 212 (30.2) |  | 55 (24.3) | 204 (30.1) |  |
 1–2 times a week | 381 (42.2) | 95 (47.5) | 286 (40.7) |  | 101 (44.7) | 280 (41.4) |  |
 ≥ 3 times a week | 263 (29.1) | 58 (29.0) | 205 (29.2) |  | 70 (31.0) | 193 (28.5) |  |