How much weight should you gain in pregnancy?
Healthy weight gain depends on your BMI before pregnancy. For a single baby, the US Institute of Medicine recommends 12.5 to 18 kg if underweight, 11.5 to 16 kg for a healthy weight, 7 to 11.5 kg if overweight and 5 to 9 kg if obese. Most of the gain happens after 13 weeks.
Key facts
| BMI under 18.5 | 12.5 to 18 kg |
|---|---|
| BMI 18.5 to 24.9 | 11.5 to 16 kg |
| BMI 25 to 29.9 | 7 to 11.5 kg |
| BMI 30 or more | 5 to 9 kg |
| First trimester | Usually 0.5 to 2 kg |
Where the weight goes
At full term, a typical gain is made up of the baby (about 3.4 kg), placenta, amniotic fluid, a larger womb and breasts, extra blood and fluid, and some fat stored for breastfeeding.
Check your range
Enter your height and weights in our weight gain calculator to see the healthy range for your current week, plotted on a chart.
Staying on track
- Don't diet in pregnancy. Focus on vegetables, protein, whole grains and pasteurised dairy.
- You don't need extra calories until the last 3 months, and then only about 200 a day.
- Stay active: walking, swimming and pregnancy yoga.
- Cut back on sweets, sugary chai and fried snacks rather than whole meals.
Gaining too little or too much
Gaining too little can affect your baby's growth. Gaining too much raises the risk of gestational diabetes, high blood pressure and a large baby. If you're outside the range, talk to your doctor rather than making big changes alone.
A note for South Asian women
Some guidelines use lower BMI cut-offs for Asian populations, because health risks start at lower weights. Your doctor may use these.
Frequently asked questions
Is sudden weight gain a problem?
What if I'm pregnant with twins?
Sources
- Institute of Medicine (2009): Weight gain during pregnancy
- ACOG Committee Opinion 548
- WHO: Appropriate BMI for Asian populations
General information, not medical advice. Medical disclaimer · How we review content
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