See how much weight gain is typical for your starting BMI, and where you might be at this stage of pregnancy.
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Typical weight gain for one baby (IOM 2009)
| BMI before pregnancy | Total gain | A week after week 13 |
|---|---|---|
| Under 18.5 | 12.5 to 18 kg | 0.44 to 0.58 kg |
| 18.5 to 24.9 | 11.5 to 16 kg | 0.35 to 0.50 kg |
| 25 to 29.9 | 7 to 11.5 kg | 0.23 to 0.33 kg |
| 30 or more | 5 to 9 kg | 0.17 to 0.27 kg |
These ranges assume 0.5 to 2 kg is gained in the first 13 weeks. They come from the US Institute of Medicine and are widely used; the UK doesn’t set official targets.
Healthy eating in pregnancy
- You don’t need to “eat for two”, even with twins, though you’ll probably feel hungrier than usual.
- Don’t diet while pregnant. If you’re worried about your weight, talk to your midwife or GP.
- Stay active with walking, swimming or pregnancy exercise classes.
- Women expecting twins have different ranges, so ask your midwife.
Frequently asked questions
How much weight should I gain in pregnancy?
It depends on your BMI before pregnancy. For a healthy BMI, typical gain is 11.5 to 16 kg.
Is it OK to lose weight while pregnant?
Don’t try to lose weight while pregnant. Talk to your midwife if you’re concerned.
Does the UK have weight-gain targets?
No. These US ranges are used as a general guide.
Is anything stored?
No, it runs in your browser.
Sources
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