Healthy weight gain during pregnancy helps your baby grow and develop. It also helps lower the risk of health problems for you and your baby.
How much weight should I gain in total when I am pregnant?
The total amount of weight you should gain depends on your Body Mass Index (BMI) before you become pregnant. BMI is a number based on a comparison of your weight to your height.
Find out your pre-pregnancy BMI and recommended weight gain using the Pregnancy Weight Gain Calculator.
If you know your pre-pregnancy BMI, you can also use the following chart to determine how much weight you should gain.
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Body Mass Index
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Recommended Weight Gain
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below 18.5
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12.5 - 18 kg (28 - 40 lbs)
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18.5 - 24.9
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11.5 - 16 kg (25 - 35 lbs)
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25.0 - 29.9
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7 - 11.5 kg (15 - 25 lbs)
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above 30
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5 - 9 kg (11 - 20 lbs)
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If you are pregnant with more than one baby (e.g. twins) you will need to gain more weight. Speak with your health care provider to find out the amount of weight gain that is best for you.
How much weight should I gain each trimester?
In the first trimester you should not gain much weight. Most women gain less than 2 kg (4 ½ lbs) in the first trimester.
Most weight gain happens in the second and third trimesters when your baby is growing and developing and your body is changing to support your baby. The recommended rate of weight gain depends on your pre-pregnancy BMI.
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Pre-Pregnancy BMI
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Average weight gain in the 2nd and 3rd trimesters
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kg/week
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lb/week
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Below 18.5
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0.5
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1.0
|
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18.5 - 24.9
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0.4
|
1.0
|
|
25.0 - 29.9
|
0.3
|
0.6
|
|
Above 30
|
0.2
|
0.5
|
Your health care provider will help you keep track of your weight to make sure that you are gaining a healthy amount each trimester.
What are the risks of gaining too much or too little weight when pregnant?
If you gain more than the recommended amount of weight during pregnancy, there may be a higher risk of:
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Delivering your baby too soon
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Having a caesarean (C-section) delivery
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Developing gestational diabetes
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Keeping extra weight on after pregnancy
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Having a baby with a high birth weight (which increases the risk of a difficult birth)
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Your baby being overweight in childhood
If you gain less than the recommended amount of weight during pregnancy, there is a higher risk of:
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Delivering your baby too soon
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Having a baby with a low birth weight (which is linked to health problems for your baby)
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Difficulty starting breastfeeding
What if I’m overweight before getting pregnant?
If your pre-pregnancy BMI is 25 or higher, aim for a healthier weight before you get pregnant.
Losing weight or dieting while you are pregnant is not recommended because it could affect your baby’s growth. It is important to gain the right amount of weight based on your pre-pregnancy BMI.
What if I’m underweight before getting pregnant?
If your pre-pregnancy BMI is below 18.5, try to reach a healthier weight before you get pregnant.
If you are already pregnant, choose extra servings from Canada’s Food Guide to help you gain the recommended amount of weight based on your pre-pregnancy BMI.
You may also be interested in:
Planning to have a baby? Tips for healthy eating and more
Eating for a healthy pregnancy
Print a copy of The Sensible Guide to a Healthy Pregnancy
Last Update – February 7, 2019