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Nutrition and Weight Gain during Pregnancy

Healthy Weight Gain

​​Weight gain is an important part of pregnancy. Eating well, being physically active and gaining a healthy amount of weight during pregnancy is not only good for you, but also good for your baby.

​The recommended amount of weight gain during pregnancy depends on your body mass index (BMI) before pregnancy. Knowing the weight gain range that is healthy for you will help you to gain enough weight without gaining too much. Find out your pre-pregnancy BMI by either:

Eating well and staying active can help you to gain a healthy amount of weight.

The table below will help you find out how much weight gain will be healthy for you and your baby. These calculations assume a 0.5 to 2.0 kg (1.1 to 4.4 lb) weight gain in the first trimester.​

​​​Pre-Pregnant BMIRecommended Total Weight Gain for Pregnancy* Average Weekly Weight Gain Rate in 2nd and 3rd Trimesters*
less than 18.5​​28 to 40 lb
12.5 to 18 kg​
1 lb each week
0.5 kg each week​
​18.5 to 24.925 to 35 lb
11.5 to 16 kg​
1 lb each week
0.4 kg each week​
25.0 to 29.9​15 to 25 lb
7 to 11.5 kg​
0.6 lb each week
0.3 kg each week​
more than 30​11 to 20 lb
5 to 9 kg​
0.5 lb each week
0.2 kg each week​​

*Health Canada 2010 Gestational Weight Gain Guidelines

You don’t need to gain much weight in the first trimester, only 0.5 to2 kg (1.1 to 4.4 lb). Most of your weight gain happens in your second and third trimesters. You may gain weight a little faster or a little slower each week.

​T​oo much?

Women who gain weight above the recommended range are more likely to have:

  • more trouble giving birth
  • a higher risk for caesarean birth (C-section), high blood sugar (gestational diabetes), and high blood pressure during pregnancy
  • more trouble losing the weight after pregnancy
  • babies who are born early (preterm)
  • babies who are born large for their age or who have a high birth weight of more than 4 kg (9 lbs)
  • babies who will be above a healthy weight later in childhood

Too little?

Women who gain weight below the recommended range are more likely to have:

  • babies who are born early (preterm)
  • babies who are born small for their age or who have a low birth weight (less than 2.5 kg or 5 lbs. 8 oz.)

Weight Gain Goals for Women Carrying Twins, Triplets and More

Early weight gain is important when you’re pregnant with twins, triplets or more. This helps lower the risk of your babies being born too early and helps to increase the chance for your babies will be born at a healthy weight.

If you’re pregnant with twins, try for the following weight gain:


​​​Pre-Pregnant BMI​​Total weight gain for a twin pregnancy
​18.5 to 24.9 37 to 54 lb
17 to 25 kg​
25.0 to 29.9​31 to 50 lb
14 to 23 kg ​
​more than 30​25 to 42 lb
​11 to 19 kg ​

If you’re pregnant with triplets or more, talk to your healthcare provider about how much weight gain is best for you.​

Current as of: January 7, 2020

Author: Healthy Children and Families, Alberta Health Services