Healthy Pregnancy Weight

Healthy Pregnancy Weight2022-06-09T15:50:25-04:00
  • A family of three, including a toddler, smiling outdoors with the father holding the child. all are casually dressed and standing by wooden beams.

Pregnancy is a time when a woman’s body will go through many changes in order to provide the best environment in which her fetus can grow. Pregnancy weight gain is a normal and expected part of a healthy pregnancy. Women will gain weight based on their own individual needs and body type. However, gaining too much or not enough weight can pose significant risk to the health of mom and the fetus. There are ways that a woman can manage how much weight she gains during pregnancy in order to optimize their health and wellbeing.

The Institute of Medicine (IOM) created guidelines for ‘ideal’ weight gain during pregnancy to minimize health risks for mom and the fetus.  The ‘ideal’ weight gain differs depending on a woman’s pre-pregnancy body mass index (BMI, an indicator of body size based on height and weight). If a woman enters pregnancy with overweight (BMI ≥ 25 kg/m2) or obesity (BMI ≥ 30 kg/m2), the amount of recommended weight gain is much smaller than if she were to enter pregnancy at what the IOM considers a normal weight (BMI = 18.5-24.9 kg/m2). Starting pregnancy at a higher weight may increase the risk of negative health outcomes for mom and the unborn fetus, even if the weight gain recommendations were met.  However, by leading a healthy lifestyle known to assist with weight management, these high-risk women can reduce the chances of such negative outcomes. You can discuss this with an obstetrician, family doctor or midwife.

No matter what weight a woman enters pregnancy at, gaining more weight than what is recommended may cause problems. These include gestational diabetes mellitus (GDM), gestational hypertension, weight retention after pregnancy, the fetus growing too large, (referred to as macrosomia), having a Caesarean delivery, development of obesity and other chronic diseases later in life (like high blood pressure or heart disease) in mom and the future baby.

Women with obesity tend to gain more weight than what is recommended more often than women who don’t have obesity. Women with obesity do not necessarily gain more total weight, but rather exceed their specific recommendation for weight gain more often.

Women with obesity who exceed the pregnancy weight gain recommendations may increase their risk even more for these negative health outcomes. For example, if a mother had obesity during pregnancy, or if she gained more weight than recommended, her fetus is much more likely to be born large-for-gestational age and to be at greater risk for obesity in childhood when compared to children born from mothers without obesity or those who met their specific weight gain guidelines.

Pregnancy is an important period in a woman’s lifespan and can play an important role in preventing obesity in future generations. Therefore, it is important for a woman to be aware of the guidelines and to make efforts to stay within her recommended target zone not only for her own short-term and long-term health, but for that of her future baby as well.  There are many other factors that can influence pregnancy such as environmental factors (culture, socio-economic status, psychological health, emotional stressors) and genetics. What is most important during pregnancy, no matter what weight a woman begins pregnancy at, is to practice behaviours that promote health and wellness.

Eat Healthy

Eating healthy is an important aspect of any healthy lifestyle, regardless of your weight. However, during pregnancy it is even more important to ensure the best health for the future baby.

  • Follow the Canada Food Guide to Healthy Eating:
    • Eat a balanced diet, filled with a wide range of fruits and vegetables. There are many pre-natal vitamins and minerals that pregnant women need for a healthy pregnancy. In particular, choose foods that are rich in omega-3 fats, folic acid, and iron.
  • “Eating for two” is a myth:

In the first trimester of pregnancy a woman does not need to eat any extra calories per day. The second and third trimesters of pregnancy are associated with increased energy demands from the growing baby, meaning that more calories are required: caloric intake should increase by 340 calories per day in the 2nd trimester and 450 calories per day in the 3rd trimester.

  • A woman will meet these extra nutritional demands by adding in two-to-three extra servings from the food group(s) of her choice. Instead of thinking “eat twice as much,” think “eat twice as healthy!”

Avoid Harmful Substances

Harmful substances like cigarettes, alcohol, recreational and some prescription drugs can have a serious impact on your baby’s health. If a woman or someone close to her is engaging in any of these behaviours before pregnancy, she should talk to her healthcare provider about what supports are available to help modify these behaviours.

Healthy Sleep Habits

Getting enough sleep during pregnancy is important. There is no ‘right’ way to sleep, and no formal guidelines have been accepted by the medical community, since comfort is unique to each individual. Finding a sleeping position that is comfortable is often the greatest challenge. For example, a small number of pregnant women feel faint when lying flat.  Ultimately, each woman should find the most comfortable sleep position for them. Lack of sleep can impact pregnancy outcomes, but more importantly, it can also affect the ability to function and maintain other health behaviours.

Manage Stress

Finding ways to manage stress is important. Pregnancy is a time of change, not only within the body but also in life in general. Try to find relaxing strategies like meditation or yoga, maintain social support networks and seek out mental health support and counselling if needed.


Exercise is another way to manage stress, and it also has many great benefits for both a woman and her unborn baby! Exercise promotes healthy growth and development of the fetus, as well as promoting the woman’s physical and mental health.  Regular physical activity can also contribute to healthy weight gain throughout pregnancy.

  • It is recommended to participate in 150-300 minutes of moderate intensity exercise on each week. This intensity will be just enough to increase heart rate and break a sweat. Trained women with high pre-pregnancy fitness may be able to participate in greater amounts of exercise with higher intensity. A health care provider or appropriate allied health professional (exercise physiologist, kinesiologist) can provide guidance.
  • The “Talk Test” is a great way to check exercise intensity. For a moderate intensity, the goal is to be able to talk, but not sing, during the exercise.
  • Women should participate in activities that have a low risk of loss of balance or trauma to their baby. Examples include walking/jogging/running, swimming or stationary cycling.
  • It is also safe and recommended to do muscle strengthening exercises (two times per week) that work the whole body. Exercises should use body weight or light weight, and consist of one set of 12-15 repetitions for 8-10 exercises. It is important to breath out during the hardest part of the movement.
  • It is important for women to pay attention to the changes in their body from exercising during pregnancy, and bring up any problems with their healthcare provider.
  • It is also important to warm-up with light movements before starting exercise – cold muscles are injured more easily!
  • Most importantly, if a woman is not exercising before pregnancy, it is important that she talks to her healthcare provider prior to engaging in exercise. Always start exercising gradually, and don’t try too much at once. The goal is to be in good health during pregnancy, not to train for peak fitness.
  • Reducing sedentary time may also be beneficial in pregnancy.

If you have any concerns or questions, always ask your healthcare provider! It is better to be safe than risk your health.

Whether a woman plans on seeing a family caregiver, midwife, nurse, obstetrician or other healthcare practitioner, there’s no doubt that she and her loved ones will be learning a lot of new information regarding pregnancy.

It is important to know that women are not alone in this learning process. A healthcare team is there to help achieve a healthy pregnancy Don’t be shy; having a healthy and informative weight management conversation with a healthcare team will help a woman be fully ready to manage a healthy pregnancy!

Is it safe for me to exercise during my pregnancy?

Although physical activity is recommended in pregnancy, there is a small number of women for whom it may not safe be safe. Some medical conditions may prevent a woman from exercising safely because of the possibility of harm to her or the baby. A woman can ask her doctor about the Physical Activity Readiness Medical Examination (PARmed-X for Pregnancy). This is a guideline that will help her healthcare provider decide whether physical activity is appropriate and safe. In addition to giving a woman the go-ahead to be physically active, it also provides excellent recommendations regarding the frequency, type and intensity of exercise that you are safe to do. These recommendations are catered to each woman at each stage of pregnancy.

What types of exercise should I engage in?

A woman’s body will go through many changes during pregnancy. A shift in the centre of gravity and a decrease in joint stability are just two examples. Different types of physical activity will even impact the baby in different ways. Her healthcare practitioner will be able to explain the changes that are going on within the body and discuss the best exercises for her pregnancy. There are evidence-based resources available through the Canadian Society for Exercise Physiology and the American College of Obstetricians and Gynecologists:

Discuss your current behaviours!

It is important for women and their healthcare provider to discuss and collaboratively reflect upon current activities, behaviours, and her social environment. Their healthcare practitioner or allied health professional can help decide if these behaviours are safe to continue doing throughout pregnancy. More importantly, they will be able to suggest adjustments to current behaviours and social environmental factors that can better the health of both her and her unborn baby.

What additional resources exist to help keep me on track?

The community is filled with many resources to help a woman have a healthy pregnancy! Nutritional guides, physical activity guides, pre-natal classes, counselling services, personal training services and social services are just the beginning. A healthcare practitioner can give suggestions for additional resources that will be helpful to pregnancy.  Women experience pregnancy differently and there is no one size fits all. Each woman knows their body best and should work collaboratively with their healthcare practitioner to decide what she needs to have a healthy pregnancy.