IOM 2009 Weight Gain Guidelines
The Institute of Medicine (IOM) published evidence-based guidelines for gestational weight gain based on pre-pregnancy BMI. These are the most widely used recommendations globally.
| Pre-Pregnancy BMI | Category | Total Gain Range | Weekly Gain (2nd/3rd Tri) |
|---|---|---|---|
| < 18.5 | Underweight | 12.7 – 18.1 kg | 0.45 – 0.59 kg |
| 18.5 – 24.9 | Normal | 11.3 – 15.9 kg | 0.36 – 0.45 kg |
| 25.0 – 29.9 | Overweight | 6.8 – 11.3 kg | 0.23 – 0.32 kg |
| ≥ 30.0 | Obese | 5.0 – 9.1 kg | 0.18 – 0.27 kg |
Why Weight Gain Matters
Adequate gestational weight gain is associated with better outcomes for both mother and baby. Inadequate gain increases risks of preterm birth and SGA. Excessive gain increases risks of gestational diabetes, preeclampsia, cesarean delivery, LGA, and postpartum weight retention.
Remember: Every pregnancy is unique. These are population-level guidelines — your healthcare provider may recommend different targets based on your individual health profile.
Track your baby's growth after birth
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