A Guide to Healthy Pregnancy Weight Gain

Where does the extra weight go during pregnancy?

After your initial positive pregnancy test, you may feel a bit of ambivalence every time you step on the scale. On the one hand, you know that your amazing body is growing a baby, so you fully expect to be steadily gaining weight. On the other hand, it can be perplexing to know that you may be gaining 30 or more pounds over a 40-week period, given that the average birth weight of a newborn is only 7.5 pounds, according to experts at the University of Michigan.

During pregnancy, your metabolism and hormones kick into high gear, storing fat and nutrients. Your uterus and placenta are growing, your blood volume expands by 33 percent (about 1.5 liters, according to experts at the University of Colorado), your breast tissue expands, and you hold onto more fluid.

The American Pregnancy Association breaks down the average weight gain during pregnancy in the following manner:

• Baby: 7 to 8 pounds
• Placenta: 1 to 2 pounds
• Amniotic fluid: 2 pounds
• Uterus: 2 pounds
• Maternal breast tissue: 2 pounds
• Maternal blood: 4 pounds
• Fluids in maternal tissue: 4 pounds
• Maternal fat and nutrient stores: 7 pounds

Depending on each woman’s metabolism, health history, and pregnancy, this weight gain may vary. However, it’s helpful to get a glimpse of where some of the extra weight goes during a pregnancy.

Is it safe to lose weight when pregnant?

The answer to this question is not universal, as weight loss during pregnancy is entirely situation-specific. Some women who suffer from a condition of severe nausea and vomiting, known as hyperemesis gravidarum, lose weight during their pregnancy, particularly during the first trimester, according to the American Pregnancy Association However, when being closely supported by an OB-GYN, this weight loss can usually be managed safely. Other women who have an elevated body mass index (BMI) may be advised to lose weight while pregnant to make their pregnancy safer for both mom and fetus. However, for the grand majority of women, experts suggest not trying to diet or lose weight while pregnant, according to the American Pregnancy Association.

How to gain the right amount of weight during pregnancy

Instead of deliberately trying to lose weight while pregnant, eating a nutritious diet and doing regular, moderate exercise can help you stay within the normal pregnancy weight gain timeline, according to The American College of Gynecologists (ACOG).. Getting proper calories and nutrients is essential for providing resources to your developing fetus and supporting structures. Ask your doctor for advice about the best way to fuel your weight gain based on your particular health status.

In terms of the “right amount of weight,” it can be helpful to reference some specific calorie guideposts. ACOG suggests that if you are at a healthy pre-pregnancy weight, you may not need to gain any weight at all during the first trimester, and you do not need any extra calories. During the second trimester, you may need an extra 340 calories daily, and during the third trimester, you may need 450 extra calories a day. Try to think of these extra calories as one or two additional healthy snacks per day—such as an apple and peanut butter or eggs and avocados—instead of an excuse to eat a half-pint of ice cream.

Pregnancy weight-gain guidelines

Medical professionals who guide women through pregnancies do so with the help of a few guidelines. Check out these pregnancy weight gain charts, adapted from the U.S. Centers for Disease Control and Prevention (CDC), for a quick look at which category may apply to you.

Recommended Weight Gain for Women Pregnant with a Single Baby

Recommended Weight Gain for Women Pregnant with Twins

What if you gain too much weight during pregnancy?

If you are concerned about your weight gain during pregnancy, talk with your medical provider. According to the CDC, sometimes excessive weight gain, particularly if it happens very quickly, can be a sign of a serious medical complication. However, if you are just on the higher end or slightly past the expected weight gain timeline, then you can do several things to help manage your weight gain. These include activity modifications, like limiting your intake of junk food (high-fat or high-sugar content, with little nutritional value) and engaging in moderate exercise. However, before adopting any new habits during pregnancy, check in with your medical provider.

When to call your doctor

Now that you have a better idea of normal weight gain during pregnancy, it’s also a good idea to know when to seek medical advice. If you are experiencing any sudden changes in your weight (weight gain or weight loss), call your doctor. You should also call if you have questions about where you fall along the expected weight gain spectrum and how to stay on track.