Table 1. Maternal and infant’s characteristics according to pre-pregnancy body mass index (BMI) and gestational weight gain (GWG) (n = 510).
| Total sample (n = 510) | Pre-pregnancy BMI category |
Gestational weight gain category |
|||||
|---|---|---|---|---|---|---|---|
| Underweight (n = 120) | Normal weight (n = 336) | Overweight and obese (n = 54) | Inadequate (n = 105) | Adequate (n = 222) | Excessive (n = 183) | ||
| Maternal characteristic | |||||||
| Age (years) | |||||||
| <25 | 23 (4.5%) | 4 (3.3%) | 17 (5.1%) | 2 (3.7%) | 5 (4.8%) | 9 (4.1%) | 9 (4.9%) |
| 25–29 | 199 (39.0%) | 63 (52.5%) | 116 (34.5%) | 20 (37.0%) | 35 (33.3%) | 89 (40.1%) | 75 (41.0%) |
| 30–34 | 206 (40.4%) | 41 (34.2%) | 144 (42.9%) | 21 (38.9%) | 50 (47.6%) | 86 (38.7%) | 70 (38.3%) |
| ≥35 | 82 (16.1%) | 12 (10.0%) | 59 (17.6%) | 11 (20.4%) | 15 (14.3%) | 38 (17.1%) | 29 (15.8%) |
| Education (years) | |||||||
| ≤12 (High school) | 55 (10.8%) | 12 (10.0%) | 33 (9.8%) | 10 (18.5%) | 5 (4.8%) | 19 (8.6%) | 31 (16.9%) |
| 13–16 (Undergraduate school) | 349 (68.4%) | 82 (68.3%) | 230 (68.5%) | 37 (68.5%) | 62 (59.0%) | 163 (73.4%) | 124 (67.8%) |
| ≥17 (Postgraduate school) | 106 (20.8%) | 26 (21.7%) | 73 (21.7%) | 7 (13.0%) | 38 (36.2%) | 40 (18.0%) | 28 (15.3%) |
| Parity | |||||||
| 0 (Primiparous) | 384 (75.3%) | 99 (82.5%) | 241 (71.7%) | 44 (81.5%) | 80 (76.2%) | 163 (73.4%) | 141 (77.0%) |
| ≥1 (Multiparous) | 126 (24.7%) | 21 (17.5%) | 95 (28.3%) | 10 (18.5%) | 25 (23.8%) | 59 (26.6%) | 42 (23.0%) |
| Household monthly salary (¥) | |||||||
| <10000 | 85 (16.7%) | 22 (18.3%) | 51 (15.2%) | 12 (22.2%) | 17 (16.2%) | 33 (14.9%) | 35 (19.1%) |
| 10000–20000 | 196 (38.4%) | 50 (41.7%) | 126 (37.5%) | 20 (37.0%) | 36 (34.3%) | 82 (36.9%) | 78 (42.6%) |
| 20001–30000 | 138 (27.1%) | 30 (25.0%) | 95 (28.3%) | 13 (24.1%) | 31 (29.5%) | 64 (28.8%) | 43 (23.5%) |
| >30000 | 91 (17.8%) | 18 (15.0%) | 64 (19.0%) | 9 (16.7%) | 21 (20.0%) | 43 (19.4%) | 27 (14.8%) |
| Smoking during pregnancy | |||||||
| Yes/Lived with smoker | 155 (30.4%) | 35 (29.2%) | 106 (31.5%) | 14 (25.9%) | 76 (72.4%) | 152 (68.5%) | 127 (69.4%) |
| No | 355 (69.6%) | 85 (70.8%) | 230 (68.5%) | 40 (74.1%) | 29 (27.6%) | 70 (31.5%) | 56 (30.6%) |
| Alcohol use during pregnancy | |||||||
| Yes | 32 (6.3%) | 9 (7.5%) | 18 (5.4%) | 5 (9.3%) | 7 (6.7%) | 12 (5.4%) | 13 (7.1%) |
| No | 478 (93.7%) | 111 (92.5%) | 318 (94.6%) | 49 (90.7%) | 98 (93.3%) | 210 (94.6%) | 170 (92.9%) |
| Infant characteristic | |||||||
| Sex | |||||||
| Male | 273 (53.5%) | 62 (51.7%) | 186 (55.4%) | 25 (46.3%) | 65 (61.9%) | 103 (46.4%) | 105 (57.4%) |
| Female | 237 (46.5%) | 58 (48.3%) | 150 (44.6%) | 29 (53.7%) | 40 (38.1%) | 119 (53.6%) | 78 (42.6%) |
| Gestational age (weeks) | |||||||
| <37 | 8 (1.6%) | 3 (2.5%) | 5 (1.5%) | 0 (0.0%) | 3 (2.9%) | 4 (1.8%) | 1 (0.5%) |
| ≥37 | 502 (98.4%) | 117 (97.5%) | 331 (98.5%) | 54 (100.0%) | 102 (97.1%) | 218 (98.2%) | 182 (99.5%) |
| Birthweight (g) | |||||||
| <2500 | 5 (1.0%) | 2 (1.7%) | 3 (0.9%) | 0 (0.0%) | 2 (1.9%) | 1 (0.5%) | 2 (1.1%) |
| 2500–4000 | 470 (92.2%) | 115 (95.8%) | 307 (91.4%) | 48 (88.9%) | 97 (92.4%) | 217 (97.7%) | 156 (85.2%) |
| ≥4000 | 35 (6.9%) | 3 (2.5%) | 26 (7.7%) | 6 (11.1%) | 6 (5.7%) | 4 (1.8%) | 25 (13.7%) |
| Fetal growth | |||||||
| SGA | 32 (6.3%) | 8 (6.7%) | 23 (6.8%) | 1 (1.9%) | 15 (14.3%) | 14 (6.3%) | 3 (1.6%) |
| AGA | 424 (83.1%) | 107 (89.2%) | 272 (81.0%) | 45 (83.3%) | 83 (79.0%) | 197 (88.7%) | 144 (78.7%) |
| LGA | 54 (10.6%) | 5 (4.2%) | 41 (12.2%) | 8 (14.8%) | 7 (6.7%) | 11 (5.0%) | 36 (19.7%) |
| Birthweight (g) (mean ± SD) | 3376.9 ± 447.7 | 3268.2 ± 3367.9 | 3390.2 ± 465.0 | 3535.9 ± 447.8 | 3180.3 ± 397.8 | 3302.9 ± 365.5 | 3579.5 ± 487.4 |
| Birth length (cm) | 50.1 ± 0.7 | 50.0 ± 0.4 | 50.1 ± 0.7 | 50.2 ± 0.9 | 50.0 ± 0.6 | 50.0 ± 0.5 | 50.3 ± 0.9 |
| Head circumference (cm) | 34.2 ± 1.1 | 34.1 ± 0.9 | 34.2 ± 1.1 | 34.4 ± 1.4 | 34.0 ± 1.1 | 34.1 ± 1.0 | 34.5 ± 1.1 |