How Much Weight to Gain During Pregnancy
The right amount of pregnancy weight gain depends on your body type, BMI, and whether you’re carrying one or more babies. Here’s how to know your healthy range and how to track it safely.
Recommended Weight Gain by BMI
The Institute of Medicine (IOM) provides guidelines based on pre-pregnancy Body Mass Index (BMI). These ranges help support healthy fetal growth while avoiding complications such as gestational diabetes or high blood pressure.
| Pre-Pregnancy BMI | Total Gain (lbs) | Total Gain (kg) |
|---|---|---|
| Underweight (BMI < 18.5) | 28–40 | 12.5–18 |
| Normal weight (BMI 18.5–24.9) | 25–35 | 11.5–16 |
| Overweight (BMI 25–29.9) | 15–25 | 7–11.5 |
| Obese (BMI ≥ 30) | 11–20 | 5–9 |
These numbers reflect the total expected gain by the end of pregnancy. The pace of weight gain matters too—most occurs during the second and third trimesters as the baby and placenta grow.
How to Track Progress
Instead of checking weekly charts by hand, use the Pregnancy Weight Gain Calculator to estimate your weekly gain target, see how your current weight compares to recommendations, and visualize your progress in an easy-to-read chart.
Why Healthy Weight Gain Matters
- Supports healthy fetal growth and brain development.
- Reduces risk of preterm birth or low birth weight.
- Lowers risk of gestational diabetes and preeclampsia.
- Improves postpartum recovery and long-term health outcomes.
Common Questions
Is weight gain the same for twins?
Twin pregnancies typically require higher total gains—around 37–54 lbs (17–25 kg) for those with a normal BMI. Discuss your specific needs with your provider.
What if I’m not gaining weight in the first trimester?
Early pregnancy nausea can temporarily reduce appetite or cause weight loss. As long as you stay hydrated and your weight stabilizes by the second trimester, it’s usually fine.
Does BMI really matter that much?
It helps personalize your goals. People with lower BMIs need more fat reserves to support pregnancy, while those with higher BMIs need a slower, steadier gain.