Table. Comparison of GWG IQRs Assessed Using the Study Population and IOM Recommendations.
| BMI category | GWG ranges | IOM recommendations | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statistics-based approach | Outcome-based approach | |||||||||||
| Optimal range | GWG rate | Optimal range | GWG rate | IQR | GWG rate | |||||||
| kg | lb | kg/wk | lb/wk | kg | lb | kg/wk | lb/wk | kg | lb | kg/wk | lb/wk | |
| Underweight (BMI <18.5) | 15.9-22.7 | 35.1-50.0 | 0.44-0.63 | 0.97-1.39 | 17.5-24.9 | 38.6-54.9 | 0.49-0.69 | 1.07-1.52 | ND | ND | ND | ND |
| Normal weight (BMI 18.5-24.9) | 15.4-22.7 | 34.0-50.0 | 0.43-0.63 | 0.94-1.39 | 15.0-24.9 | 33.1-54.9 | 0.42-0.69 | 0.92-1.52 | 16.8-24.5 | 37.0-54.0 | 0.45-0.66 | 1.03-1.50 |
| Overweight (BMI 25.0-29.9) | 12.7-22.2 | 28.0-48.9 | 0.35-0.62 | 0.78-1.36 | 15.0-24.9 | 33.1-54.9 | 0.42-0.69 | 0.92-1.52 | 14.1-22.7 | 31.1-50.0 | 0.38-0.61 | 0.86-1.39 |
| Class 1 obesity (BMI 30.0-34.9) | 10.0-20.0 | 22.0-44.1 | 0.28-0.56 | 0.61-1.22 | 10.0-19.9 | 22.0-43.9 | 0.28-0.55 | 0.61-1.22 | 11.3-19.1 | 24.9-42.1 | 0.31-0.51 | 0.69-1.17 |
| Class 2 obesity (BMI 35.0-39.9) | 7.7-18.1 | 17.0-39.9 | 0.21-0.50 | 0.47-1.11 | 7.5-17.4 | 16.5-38.4 | 0.21-0.48 | 0.46-1.07 | ND | ND | ND | ND |
| Class 3 obesity (BMI ≥40.0) | 5.9-16.3 | 13.0-35.9 | 0.16-0.45 | 0.36-1.00 | 5.0-9.9 | 11.0-21.8 | 0.14-0.28 | 0.31-0.61 | ND | ND | ND | ND |
Abbreviations: BMI, body mass index calculated as weight in kilograms divided by height in meters squared; GWG, gestational weight gain; IOM, US Institute of Medicine; ND, not determined.