Table 1 Characteristics of parent-newborn pairs according to maternal pre-pregnancy BMI
Characteristics | UW (n = 255) | NW (n = 753) | OW (n = 74) | P-value |
|---|---|---|---|---|
Newborn | ||||
 sex |  |  |  | 0.008 |
  Female | 139 (54.5%) | 331 (44.0%) | 30 (40.5%) |  |
  Male | 116 (45.5%) | 422 (56.0%) | 44 (59.5%) |  |
 Gestational age, weeks | 38.67 (1.19) | 38.65 (1.26) | 38.68 (1.23) | 0.963 |
 Birth weight, g | 3006.75 (360.39) | 3144.57 (379.27) | 3264.05 (421.81) | < 0.001 |
Maternal | ||||
 Age, years | 26.68 (4.99) | 28.75 (5.12) | 32.46 (4.50) | < 0.001 |
Residential place | Â | Â | Â | 0.658 |
 Urban areas | 14 (5.5) | 49 (6.5) | 6 (8.1) |  |
 Rural areas | 241 (94.5) | 704 (93.5) | 68 (91.9) |  |
 Parity, n |  |  |  | < 0.001 |
  1 | 138 (54.1%) | 283 (37.6%) | 19 (25.7%) |  |
  ≥ 2 | 117 (45.9%) | 470 (62.4%) | 55 (74.3%) |  |
 Gravidity, n |  |  |  | < 0.001 |
  1 | 82 (32.2%) | 145 (19.3%) | 8 (10.8%) |  |
  ≥ 2 | 173 (67.8%) | 608 (80.7%) | 66 (89.2%) |  |
 Drinking pre-pregnancy, n |  |  |  | 0.361 |
  No | 248 (97.3%) | 733 (97.3%) | 74 (100%) |  |
  Yes | 7 (2.7%) | 20 (2.7%) | 0 (0.0%) |  |
 Smoking pre-pregnancy, n |  |  |  | 0.657 |
  No | 254 (99.6%) | 752 (99.9%) | 74 (100%) |  |
  Yes | 1 (0.4%) | 1 (0.1%) | 0 (0.0%) |  |
 Passive smoking during pregnancy, n |  |  | 0.919 | |
  No | 97 (38.0%) | 294 (39.0%) | 30 (40.5%) |  |
  Yes | 158 (62.0%) | 459 (61.0%) | 44 (59.5%) |  |
 Pregnancy comorbidities or complications, n |  |  | 0.081 | |
  No | 231 (90.6%) | 659 (87.5%) | 60 (81.1%) |  |
  Yes | 24 (9.4%) | 65 (12.5%) | 14 (18.9%) |  |
Cesarean section, n | 59 (23.1%) | 220 (29.2%) | 24 (32.4%) | 0.119 |
Paternal | ||||
 Age, years | 29.33 (5.20) | 31.72 (5.60) | 35.49 (4.96) | < 0.001 |
 Drinking pre-pregnancy, n |  |  |  | 0.204 |
  No | 46 (18.0) | 99 (13.1) | 14 (18.9) |  |
  Yes | 117 (45.9) | 338 (44.9) | 31 (41.9) |  |
  Missing | 92 (36.1) | 316 (42.0) | 29 (39.2) |  |
 Smoking pre-pregnancy, n |  |  |  | 0.366 |
  No | 63 (24.7) | 192 (25.5) | 18 (24.3) |  |
  Yes | 100 (39.2) | 245 (32.5) | 27 (36.5) |  |
  Missing | 92 (36.1) | 316 (42.0) | 29 (39.2) |  |
 BMI, kg/m2 | 21.85 (1.61) | 22.17 (1.36) | 22.24 (1.62) | 0.007 |
 BMI categories, n |  |  |  | 0.751 |
  HW | 237 (92.9%) | 691 (91.8%) | 67 (90.5%) |  |
  OW | 18 (7.1%) | 62 (8.2%) | 7 (9.5%) |  |