How much weight should I gain in pregnancy?

Every pregnant woman gains weight differently so there are no official guidelines for how much weight you should gain. The most important thing is to keep your weight gain to a safe and healthy level for you and your baby.

Only some of the weight you gain in pregnancy will be body fat. The other things causing weight gain will include:

• your baby
• the placenta
• the amniotic fluid (the water surrounding your baby)
• your growing breasts
• the increased blood you need
• natural fluid retention.

Some women may even lose weight during the first few months, especially if they have morning sickness, and that is absolutely normal. But don't try to lose weight while you're pregnant as this is not healthy for you or your baby.

You probably won’t be weighed at each antenatal visit if you are within a healthy weight range. But if you have an underweight or overweight body mass index (BMI) your doctor or midwife may weigh you more often because there are more potential risks for you and your baby.

What is the 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 got pregnant. There are no official guidelines in the UK but the American College of Obstetricians and Gynecologists say 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).

The recommended weight gain for women expecting twins is:

• women in the normal weight range (BMI of 18.5-24.9) are recommended to put on between 37-54 lbs (16.8-24.5kg)
• women who are overweight (BMI between 25 and 29.9) are recommended to put on between 31-50 lbs (14.1-22.7kg)
• women who are affected by obesity (BMI of 30 or more), are recommended to put on between 25-42 lbs (11.3-19.1kg).

Work out your BMI with our calculator.

Try not to get too concerned about these guidelines. The most important thing is to keep your weight gain to a safe and healthy level for you and your baby.

Your doctor or midwife will be able to advise and reassure you about what is right for you. If you are underweight or overweight, you should get extra care and support during your pregnancy.

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

For most women, if you have always been active, continuing to exercise at the same level during pregnancy is safe and healthy.

If you are not used to being active, try doing some gentle exercise for about 15 minutes a day, three times a week before building up slowly to 30 minutes a day. Remember, you’re not trying to get as fit as possible, you just need to stay physically active. You can do most types of exercises in pregnancy  so there are lots of things you can try.

If doing physical activities is difficult, just try not to stay sitting down for long periods of time. Try to walk as much as you can and make small changes to increase your daily physical activity. For example, take the stairs instead of the lift at work, or get off the bus a stop earlier.

Find out more about exercising in pregnancy.

Try to eat well, too. There is no need to 'eat for two' [or todrink full-fat milk. You do not need extra calories until the third trimester (at which point you only need an extra 200 calories).

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

The key is to 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.

Don’t forget to ask your midwife or doctor for support if you need it. They are there to help and won’t judge you.