Table 1. Characteristics of participants classified by pre-pregnancy body mass index values.
| Maternal prepregnancy BMI category | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Underweight | Normal weight | Overweight | Obese | All participants | |||||||
| FB n = 4467 |
NFB n = 6180 |
FB n = 20190 |
NFB n = 28103 |
FB n = 1416 |
NFB n = 3090 |
FB n = 267 |
NFB n = 756 |
FB n = 26340 |
NFB n = 38129 |
||
| Age (year) | 30.3±4.72 | 30.2±5.08 | 31.1±4.70 | 31.4±5.09 | 31.5±4.75 | 31.8±5.09 | 31.5±4.73 | 31.8±4.99 | 31.0±4.71 | 31.3±5.11 | |
| Height (cm) | 158.8±5.28 | 158.4±5.41 | 158.3±5.23 | 158.0±5.34 | 157.8±5.35 | 157.5±5.42 | 158.1±5.23 | 158.1±5.51 | 158.3±5.25 | 158.1±5.36 | |
| Pre-pregnancy weight (kg) | 44.7±3.37 | 44.3±3.47 | 52.2±5.12 | 52.5±5.32 | 66.7±5.57 | 66.7±5.68 | 81.4±7.91 | 82.4±9.30 | 52.0±7.34 | 52.9±8.48 | |
| BMI before pregnancy (kg/m2) | 17.7±0.67 | 17.6±0.72 | 20.8±1.58 | 21.0±1.65 | 26.7±1.33 | 26.9±1.38 | 32.6±2.46 | 32.9±2.84 | 20.7±2.66 | 21.2±3.13 | |
| Weight at delivery (kg) | 55.5±4.73 | 55.4±5.05 | 62.8±6.20 | 63.2±6.50 | 75.0±6.85 | 75.2±7.20 | 86.7±8.59 | 88.1±9.75 | 62.5±7.70 | 63.4±8.66 | |
| Weight gain during pregnancy (kg) | 10.9±3.26 | 11.1±3.52 | 10.6±3.49 | 10.7±3.74 | 8.4±4.45 | 8.5±4.85 | 5.3±5.13 | 5.6±5.19 | 10.5±3.61 | 10.5±3.96 | |
| Gestational week at delivery (week) | 39.4±1.05 | 39.4±1.09 | 39.5±1.08 | 39.5±1.12 | 39.5±1.14 | 39.5±1.17 | 39.7±1.17 | 39.5±1.21 | 39.5±1.08 | 39.5±1.12 | |
| Primiparous (%) | 1702 (38) | 3028 (49) | 7091 (35) | 12843 (46) | 386 (27) | 1153 (37) | 75 (28) | 268 (35) | 9254 (35) | 17292 (45) | |
| Current marital status (%) | |||||||||||
| Married | 4258 (96) | 5702 (94) | 19394 (97) | 26571 (96) | 1373 (98) | 2944 (96) | 256 (97) | 718 (96) | 25281 (97) | 35935 (95) | |
| Single (never married) | 140 (3.2) | 326 (5.3) | 558 (2.8) | 1034 (3.7) | 27 (1.9) | 95 (3.1) | 7 (2.7) | 25 (3.3) | 732 (2.8) | 1480 (3.9) | |
| Divorced or Widowed | 24 (0.5) | 73 (1.2) | 81 (0.4) | 227 (0.8) | 5 (0.4) | 26 (0.8) | 1 (0.4) | 5 (0.7) | 111 (0.4) | 331 (0.9) | |
| Smoking during breastfeeding period (%) | 114 (2.6) | 343 (5.6) | 356 (1.8) | 1238 (4.4) | 38 (2.7) | 189 (6.1) | 13 (4.9) | 54 (7.1) | 521 (2.0) | 1824 (4.8) | |
| Alcohol intake during breastfeeding period (%) | 109 (2.4) | 285 (4.6) | 593 (2.9) | 1328 (4.7) | 40 (2.8) | 152 (4.9) | 7 (2.6) | 32 (4.2) | 749 (2.8) | 1797 (4.7) | |
| Education (years) | |||||||||||
| <12 (%) | 170 (3.8) | 340 (5.6) | 516 (2.6) | 1248 (4.5) | 57 (4.1) | 188 (6.2) | 23 (8.8) | 58 (7.8) | 766 (2.9) | 1834 (4.9) | |
| 12–14 (%) | 3093 (70) | 4471 (73) | 14178 (71) | 20615 (74) | 1095 (78) | 2410 (79) | 203 (78) | 604 (81) | 18569 (71) | 28100 (75) | |
| >14 (%) | 1158 (26) | 1307 (21) | 5329 (27) | 5910 (21) | 255 (18) | 456 (15) | 36 (14) | 84 (11) | 6778 (26) | 7757 (21) | |
Mean±SD.
BMI: body mass index, FB: full breast-feeding, NFB: non full breast-feeding, weight gain during pregnancy = (weight at delivery)-(pre-pregnancy weight).