Table 1. Demographic characteristics of the subjects.
| Variable | Born in summer (n=1,642) | Born in winter (n=1,702) | Total (n=3,344) | P value |
|---|---|---|---|---|
| Sex | 0.593 | |||
| Male | 828 (50.43) | 875 (51.41) | 1,703 (50.93) | |
| Female | 814 (49.57) | 827 (48.59) | 1,641 (49.07) | |
| Age (yr) | 8.75±1.87 | 8.84±1.8 | 8.79±1.84 | 0.15 |
| Height (cm) | 135.55±12.6 | 135.22±12.73 | 135.39±12.67 | 0.631 |
| Body weight (kg) | 32.32±9.52 | 32.36±10.87 | 32.34±10.23 | 0.766 |
| Body mass index (kg/m2) | 17.29±2.77 | 17.46±4.48 | 17.38±3.74 | 0.487 |
| Type of delivery | 0.106 | |||
| NSVD | 933 (56.82) | 1,015 (59.64) | 1,948 (58.25) | |
| C-section | 709 (43.18) | 687 (40.36) | 1,396 (41.75) | |
| Use of antibiotics before the age of 12 months | 1,219 (74.24) | 1,261 (74.09) | 2,480 (74.16) | 0.953 |
| No | 423 (25.76) | 441 (25.91) | 864 (25.84) | |
| Yes | ||||
| Breast feeding more than 3 months | 0.220 | |||
| No | 734 (44.7) | 724 (42.54) | 1458 (43.6) | |
| Yes | 908 (55.3) | 978 (57.46) | 1,886 (56.4) | |
| Parental history of allergic diseases | ||||
| Asthma | 44 (2.68) | 50 (2.94) | 94 (2.81) | 0.729 |
| Allergic rhinitis | 499 (30.39) | 505 (29.67) | 1,004 (30.02) | 0.678 |
| Atopic dermatitis | 95 (5.79) | 114 (6.7) | 209 (6.25) | 0.309 |
| Food allergy | 72 (4.38) | 78 (4.58) | 150 (4.49) | 0.847 |
Values are presented as number (%) or mean±standard deviation.
NSVD, normal spontaneous vaginal delivery.