Table 2. Variation of birth weight, total GWG and mean weight gain per week with GWG category in each of the three prepregnancy BMI groups.
| BMI | GWG category according to IOM | N (%) | Birth weight (g) | Total gestational weight gain (kg) | Mean weight gain per week (kg) |
|---|---|---|---|---|---|
| Underweight | Inadequate | 46 (18.1) | 2928 ± 455* | 10.7 ± 1.7* | 0.28 ± 0.05* |
| Adequate | 114 (44.9) | 3271 ± 368* | 14.9 ± 1.4* | 0.38 ± 0.04* | |
| Excessive | 94 (37.0) | 3426 ± 366* | 20.7 ± 3.8* | 0.52 ± 0.09* | |
| Normal weight | Inadequate | 307 (14.3) | 3169 ± 526* | 9.0 ± 1.8* | 0.23 ± 0.05* |
| Adequate | 717 (33.3) | 3279 ± 543* | 13.8 ± 1.2* | 0.35 ± 0.03* | |
| Excessive | 1128 (52.4) | 3456 ± 485* | 19.3 ± 3.0* | 0.49 ± 0.08* | |
| Overweight | Inadequate | 51 (9.0) | 3237 ± 587* | 4.4 ± 1.7* | 0.12 ± 0.05* |
| Adequate | 138 (24.3) | 3424 ± 457† | 9.0 ± 1.7* | 0.23 ± 0.04* | |
| Excessive | 378 (66.7) | 3532 ± 421† | 16.4 ± 54.2* | 0.41 ± 0.11* |
Data presented as n (%) or mean ± standard deviation. BMI, body mass index; GWG, gestational weight gain; IOM, Institute of Medicine. *P < 0.05 vs. both the other GWG groups; †P < 0.05 vs. inadequate GWG group.