How much weight should I gain in pregnancy?

Healthy weight gain during pregnancy varies a lot between different women.

The amount of weight you should put on can depend on how much you weighed before you become pregnant.

Normal and healthy weight gain during pregnancy will include your placenta, your womb and the amniotic fluid as well as your growing baby. Some fat will also be stored for making milk when your baby is born.

Every pregnant woman gains weight differently, so you will probably not be weighed at each antenatal visit. However, your doctor or midwife might want to keep a closer eye on your weight gain if they think this will help to reduce the risks to you or your baby.

Doctors find it hard to say how much women should gain in pregnancy in general because everyone is different. Some women may even lose weight during the first few months, especially if they have morning sickness. For healthy weight gain during pregnancy women should not try to diet at this time or any time in pregnancy but weight loss might happen from sickness.

Average weight gain in pregnancy

Most women put on between 10kg (22lb) and 12.5kg (28lb) during their pregnancy.

Your healthy weight gain during pregnancy may depend on the weight you were before you became pregnant. There are no official guidelines in the UK but in the US, guidelines suggest that

  • women who are underweight (BMI under 18.5) are recommended to put on between 28-40 lbs (13-18kg)
  • women in the normal weight range (BMI of 18.5-24.9) are recommended to put on between 25-35lbs (11-16kg)
  • women who are overweight (BMI between 25 and 29.9) are recommended to put on between 15-25lbs (7-11kg)
  • women who are affected by obesity (BMI of 30 or more), are recommended to put on between 11-20 lbs (5-9kg).

Work out your BMI with our calculator.

Dieting or losing weight during pregnancy through dieting is not recommended as it may harm your unborn baby. But if you are overweight or obese and pregnant, making healthy changes to your diet can help you not to gain any weight, and you might even lose a small amount. The Royal College of Obstetricians and Gynaecologists says that this is not harmful.

The most important thing is to keep your weight gain to a safe and healthy level for you and your baby. Talk to your doctor or midwife if you're worried about how much weight you should be putting on and they will be able to advise and reassure you about what is right for you. If you are underweight or overweight, you are likely to get extra care and support during your pregnancy.

How can I manage how much weight I put on during my pregnancy?

Pregnancy is not the time to make lots of sudden big changes but neither is it a time to sit back and 'eat for two'.

Staying active is safe and healthy for you and your baby, and you do not need extra calories until the third trimester (at which point you only need an extra 200 calories).

If you are not used to eating well and being active, you can make small changes gradually to improve your diet and the amount of activity you do. There are some tips to help you set goals here.

Instead of starting a tough exercise regime you can incorporate more activity into your normal life. There are lots of ideas in this section and in our section about being active in pregnancy.

You can also find out about healthy eating and get some great tips for easy meals and snacks in our section about eating well in pregnancy. 

Find out more about your BMI

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  1. Institute of Medicine (2009) Weight Gain During Pregnancy: Re-examining the Guidelines
  2. NICE (2010)  Dietary interventions and physical activity interventions for weight management before, during and after pregnancy, Public health guidance 27, 2010
  3. RCOG (2011) Why your weight matters during pregnancy and after birth 
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Last reviewed on February 1st, 2015. Next review date February 1st, 2018.

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