Scientific studies have proven that women who gain a healthy amount of weight during pregnancy have fewer complications in their pregnancies. They are less likely to have dangerously high blood pressure or to need a Caesarean delivery. Their babies are more likely to weigh a healthy amount at birth. New studies even show that their babies have less chance of being obese or getting diabetes when they grow up.
If you wonder how much weight you should gain during your pregnancy, you may be surprised to hear that the right amount differs for everyone. Factors include whether you are starting pregnancy at a healthy weight, and if you are carrying just one baby, twins or triplets. Your doctor or midwife can help you figure out the weight gain goal that is right for you.
The weight that you were at before your pregnancy began is one of the most important factors in figuring out how much to gain. A woman who starts her pregnancy with a healthy weight should usually gain 11.5 to 16 kilograms (25 to 35 pounds).
If you start your pregnancy underweight, your doctor may suggest that you try to gain extra weight, so your unborn baby is well nourished. You may be advised to gain less if you were overweight when the pregnancy began, as it helps reduce your risk of complications.
|BMI before pregnancy||Recommended
|Less than 18.5||12.5 to 18 kg (28 to 40 lb)|
|Between 18.5 and 24.9||11.5 to 16 kg (25 to 35 lb)|
|Between 25 and 29.9||7 to 11.5 kg (15 to 25 lb)|
|More than 30||At least 7 kg (15 lb)|
|(Source: The Society of Obstetricians and Gynaecologists of Canada)|
Knowing your body mass index (BMI) makes it easier to get an idea of how much you should gain. Many free online calculators can assess your BMI based on your weight and height. Most doctors consider the healthiest BMI to be between 18.5 and 24.9. A BMI less than 18.5 is underweight, and 25 or higher is overweight.
Once you have figured out your BMI, take a look at the chart at the right. It will give you an idea of how much weight your health care provider might advise you to gain in pregnancy.
You can see that underweight pregnant women will need to gain a lot more weight than overweight women. It may be surprising to realize that even very overweight women should try to gain some weight during pregnancy. This ensures that a growing baby gets the necessary vitamins, minerals and nutrients it needs from the extra foods the mother eats.
Even if you are very overweight or feel you have gained too much, pregnancy is never the right time to try to lose weight. Do it before pregnancy if possible, or wait until after your baby is born.
Most of the weight you gain will probably be during the second half of the pregnancy, when the baby grows fastest. You may not gain much, or anything, in the first few months. Usually that is okay. If your goal is to gain 11.5 to 16 kilograms (25 to 35 pounds), by the second trimester (starting at week 13) you should start gaining about 0.4 kilograms (one pound) per week. Some weeks you may gain more, and others you may gain less. As long as the general trend is fine, do not worry too much if this happens. Your health care provider can help you figure out if you are on the right track.
In addition to helping set weight gain goals for your pregnancy, your doctor or midwife can advise how to gain weight in a healthy way, neither too much or too little.
You may be wondering how to gain the recommended amount of weight. In the first trimester (the first 12 weeks of pregnancy), you do not need to do much differently. If you find that you are more hungry than usual, you may want to add a small serving of any healthy food each day. About 100 calories is usually enough. For instance, have an extra slice of whole wheat bread, a small piece of fish or some fresh vegetables. In the second and third trimesters (starting at 13 weeks until delivery), take in an extra 200 calories per day, or about two extra servings of any healthy food.
Exercise is also important. It may keep you from gaining too much weight, and also helps with many common aches and pains of pregnancy. It can even improve your mood and help you deal with stress. Labour is easier if you are fit and strong – pushing a baby out is hard work! If you were active before you got pregnant, and do not have any complications, you can probably continue most of your usual exercise routine. Ask your health care provider if you will need to change any of your normal activities.
If you did not exercise before you got pregnant, this can be a good time to get into a healthy new habit. Your doctor or midwife can make suggestions. If the pregnancy is normal, it is usually fine to start walking, swimming, or doing another activity to stay healthy.
As your pregnancy progresses, your doctor or midwife will check to see if you are on track with your weight. If you are not gaining enough, try eating larger portions or an extra snack. You can also add foods that are higher in calories but still healthy, like nuts and cheese.
If you are gaining too much, try reducing unhealthy foods in your diet, eating smaller portions, and exercising a little more. As well, swap out high-calorie foods in your diet for lower-calorie ones. For instance, choose skim or one per cent instead of whole milk. Rather than juice or soda, drink water with a slice of orange or a few frozen berries.
If you need more ideas on how to gain the right amount of weight, ask your doctor or midwife. You may be referred to a registered dietitian, who can review what you are eating and make helpful suggestions.