How does your weight affect your pregnancy?
Most pregnant women have healthy babies—and that includes women who are obese. But being very heavy does increase the chance of problems.
Babies born to mothers who are obese have a higher risk of:
- Birth defects, such as a heart defect or neural tube defects.
- Being too large. This can cause problems during labour and delivery.
Mothers who are obese have a higher risk of:
- Problems during pregnancy, such as high blood pressure, gestational diabetes, or pre-eclampsia.
- Caesarean (or C-section) birth and a higher risk of problems from it.
- Preterm birth.
- Miscarriage or stillbirth.
If you're not pregnant already, being obese can make it hard to get pregnant.
But if you are obese, you can do a lot to improve your chances of having a healthy pregnancy.
Work with your doctor to get the care you need. Go to all your doctor visits, and follow your doctor's advice about what to do and what to avoid during pregnancy.
Should you try to lose weight during pregnancy?
No. Pregnancy is not the time to lose weight. Your baby needs you to eat a well-rounded diet. Don't cut out food groups or go on any type of weight-loss diet.
How much weight should you gain during pregnancy?
Experts recommend that obese women gain about 5 kg (11 lb) to 9 kg (20 lb). Your doctor will work with you to set a weight goal that's right for you. In some cases, a doctor may recommend that a woman not gain any weight.
Although pregnant women often joke that they're "eating for two," you don't need to eat twice as much food. In general, pregnant women need to eat about 340 extra calories a day in their second trimester. Women in their third trimester need to eat about 450 extra calories a day.footnote 3 This is about 2 or 3 extra food guide servings a day.footnote 1 You can get about 340 calories in a peanut butter sandwich. Having a cup of 1% milk with a peanut butter sandwich is about 450 calories.
How much can you eat during pregnancy?
How much you can eat depends on:
- How much you weigh when you get pregnant.
- Your body mass index (BMI).
- How much you exercise.
Like any pregnant woman, you need to eat a variety of foods from all the food groups. You especially need to make sure to get enough calcium and folic acid. It can be hard for women to get extra folic acid from food. Experts recommend taking a daily supplement that has at least 400 mcg of folic acid.footnote 2 Some women need higher doses. Talk with your health professional about how much folic acid you need. Follow your doctor's advice about how to get higher amounts of folic acid. Don't just take more multivitamins. You could get too much of the other substances that are in the multivitamin.
You may want to work with a dietitian to help you plan healthy meals to get the right amount of calories for you.
How will your prenatal care change if you're obese?
You will have the same number of doctor visits as a woman of average weight, unless you start to have problems. Then you would see your doctor more often. But you'll have the same type of tests to look for problems and make sure your baby is healthy.
What can you do to have a healthy pregnancy?
The best things you can do to have a healthy pregnancy are to eat a variety of foods, get regular exercise, avoid alcohol and smoking, and go to your doctor visits. If you didn't exercise much before you got pregnant, talk to your doctor about how you can slowly get more active.
For more information on healthy habits, see the topic Quick Tips: Healthy Pregnancy Habits.
For more information on eating well when you're pregnant, see:
- Healthy Eating: Changing Your Eating Habits.
- Healthy Eating: Making Healthy Choices When You Shop.
- Healthy Eating: Cutting Unhealthy Fats From Your Diet.
- Quick Tips: Adding Fruits and Vegetables to Your Diet.
- Meal Planning: Menu and Grocery List ( What is a PDF document? ).
If you're not pregnant yet, what can you do to get ready for pregnancy?
If you're not yet pregnant, now is a good time to try to lose some weight. Losing even 2 to 5 kilograms may help reduce your risk for problems.
You also can make other lifestyle changes to get a future pregnancy off to a good start. These include getting enough folic acid, avoiding alcohol and smoking, and avoiding or limiting caffeine. Women who are planning to get pregnant should take a folic acid supplement every day for at least 2 to 3 months before trying to get pregnant.footnote 2 See your doctor for a checkup before you become pregnant.
For more information on getting ready for pregnancy, see the topic Preparing for a Healthy Pregnancy.
Some women may want to have weight-loss surgery. If you're thinking about it, talk with your doctor to learn how it might affect a future pregnancy. For more information, see the topic Pregnancy After Bariatric Surgery.
Health Tools help you make wise health decisions or take action to improve your health.
- Health Canada (2009). Prenatal nutrition guidelines for health professionals: Background on Canada's Food Guide. Available online: http://www.hc-sc.gc.ca/fn-an/pubs/nutrition/guide-prenatal-eng.php.
- Wilson RD, et al. (2015). Pre-conception folic acid and multivitamin supplementation for the primary and secondary prevention of neural tube defects and other folic acid-sensitive congenital anomalies. SOGC Clinical Practice Guideline No. 324. Journal of Obstetrics and Gynaecology Canada 37(6): 534–549. http://sogc.org/wp-content/uploads/2015/06/gui324CPG1505E.pdf. Accessed July 20, 2015.
- Kaiser LL, Campbell CG (2014). Practice paper of the academy of nutrition and dietetics: Nutrition and lifestyle for a healthy pregnancy outcome. eatrightPro. http://www.eatrightpro.org/resource/practice/position-and-practice-papers/practice-papers/practice-paper-nutrition-and-lifestyle-for-a-healthy-pregnancy-outcome. Accessed November 16, 2017.
Other Works Consulted
- Wilson DR (2010). Obesity in pregnancy. SOGC Clinical Practice Guideline No. 239. Journal of Obstetrics and Gynaecology Canada, 32(2): 165–173.
Primary Medical Reviewer Sarah Marshall, MD - Family Medicine
Brian D. O'Brien, MD - Internal Medicine
Adam Husney, MD - Family Medicine
Kathleen Romito, MD - Family Medicine
Elizabeth T. Russo, MD - Internal Medicine
Specialist Medical Reviewer Kirtly Jones, MD - Obstetrics and Gynecology
Rebecca Sue Uranga, MD - Obstetrics and Gynecology
Current as ofDecember 11, 2017
Current as of: December 11, 2017
Author: Healthwise Staff
Medical Review: Sarah Marshall, MD - Family Medicine & Brian D. O'Brien, MD - Internal Medicine & Adam Husney, MD - Family Medicine & Kathleen Romito, MD - Family Medicine & Elizabeth T. Russo, MD - Internal Medicine & Kirtly Jones, MD - Obstetrics and Gynecology & Rebecca Sue Uranga, MD - Obstetrics and Gynecology