How much weight should I gain in pregnancy?

Everyone is different, but the amount of weight you should may depend on how much you weighed before you became pregnant.

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.

Read more


NICE Guidelines (2010) Weight management before, during and after pregnancy National Institute for Health and Care Excellence

NHS Choices. How much weight will I put on in pregnancy? (Page last reviewed: 21/12/2015. Next review due: 30/11/2018)

American College of Obstetricians and Gynecologists Weight gain during pregnancy (Page last reviewed: 2018)

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    Last reviewed on October 25th, 2018. Next review date October 25th, 2021.

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    Please note that these comments are monitored but not answered by Tommy’s. Please call your GP or maternity unit if you have concerns about your health or your baby’s health.
    • By shenky morakhiya (not verified) on 18 Apr 2020 - 13:05

      I just got complete my 7th month of pregnancy and my weight gained by 9kgs almost throughout these 7 months. is it okay for a healthy baby???

    • By Priscilla (not verified) on 11 Jan 2020 - 11:36

      I weigh 58kg and I am 26weeks am I still okay.

    • By Elizabeth (not verified) on 20 May 2019 - 13:48

      Site says you dont need any extra calories until 3rd trimester, but does that assume you already eat 2000 calories a day? I was slightly obese before pregnancy (25.* BMI depending on the day). I ate roughly 1400 calories a day, sometime more, but often less, and always tried to keep my minimum to 1200 cal. I wasn't dieting, I just was tracking calories to ensure I met a daily minimum as I am on a medicine that has a side effect of suppressing appetite (which medicine I am still on as I need it to function). I'm now 17 weeks, didnt have bad morning sickness (never vomitted), and have only lost about 1kg since becoming pregnant. I understand my baby is still tiny and so her relative needs are small, but should I be adjusting my minimum calorie intake at this trimester? My doctor just says eat more if I'm hungry and seems to care only about the upper calorie bound, which I never come close to anymore. What should my minimum be? I have a sedentary job, but have been trying to add more exercise even before becoming pregnant. It is getting harder to find any energy for it though. In my first trimester I thought I understood the drop in energy, but my energy keeps slowly dropping so I'm starting to wonder if I'm eating enough. I'm constantly exhausted.
      My "higher energy days", where I'm tired but not quite so drained, are generally days that I ate roughly 1400 calories, but there are so many other variables that I dont know if that number is cause or coincidence. If there isnt a minimum guideline, how can I figure out if I'm eating enough?

      NOTE: My last pregnancy I gained weight from mid-1st trimester until about week 25, then stopped gaining until baby was born due to gestational diabetes and its diet (that took away most foods I normally ate, which included lots of sweets, and made carb counting my only goal). I met my pre pregnancy weight less than a week after baby was born (and quickly dropped 10kg after that before it stabilized and slowly returned back up to my normal after holidays when my liking of sweets returned). This pregnancy I have disliked nearly any sweets from the start so I fear GD may be returning (even though my A1C numbers were great at week 9). I need to have a proper minimum calorie goal, not *just* a carb limit if that does happen. Help please?

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