Key Points
- Pregnancy weight gain varies from woman to woman, depending on factors such as pre-pregnancy weight, health status, genetics, and pregnancy dynamics. The extra weight during pregnancy is distributed among the baby, placenta, amniotic fluid, uterus, maternal breast tissue, maternal blood, fluids in maternal tissue, and maternal fat and nutrient stores.
- Weight loss during pregnancy is situation-specific. While some women may lose weight due to severe nausea and vomiting, or if they have an elevated body mass index, most women are advised not to try to lose weight while pregnant.
- Gaining the right amount of weight during pregnancy involves eating a nutritious diet and doing regular, moderate exercise. The American College of Gynecologists suggests specific calorie intake based on the trimester of pregnancy and the pre-pregnancy weight of the woman.
- Medical professionals use guidelines for recommended weight gain during pregnancy, which vary based on the woman's pre-pregnancy weight and whether she is carrying a single baby or twins.
- Excessive weight gain during pregnancy can be a sign of a serious medical complication. If concerned about weight gain, women are advised to consult their medical provider and consider activity modifications, including limiting intake of junk food and engaging in moderate exercise.
Finding out that you’re pregnant can be simultaneously exhilarating and intimidating. While growing a “baby bump” can be a joy, it can also be a source of stress. Women who have never gone through pregnancy often have many questions about normal weight gain during pregnancy.
The pregnancy weight gain timeline varies for every woman and depends on many factors including her pre-pregnancy weight and health status, her genetics, and the dynamics of her pregnancy, according to the American Pregnancy Association. However, you can follow some helpful guidelines when it comes to 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
Pre-Pregnancy Weight | Recommended Weight Gain |
---|---|
Underweight (BMI < 18.5) | 28-40 pounds |
Normal Weight (BMI 18.5 – 24.9) | 25-35 pounds |
Overweight (BMI 25.0 – 29.9) | 15-25 pounds |
Obese (BMI > 30.0) | 11-20 pounds |
Recommended Weight Gain for Women Pregnant with Twins
Pre-Pregnancy Weight | Recommended Weight Gain |
---|---|
Underweight (BMI < 18.5) | 50-62 pounds |
Normal Weight (BMI 18.5 – 24.9) | 37-54 pounds |
Overweight (BMI 25.0 – 29.9) | 31-50 pounds |
Obese (BMI > 30.0) | 25-42 pounds |
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.
Frequently asked questions
How can I lose weight during pregnancy?
If you are wondering how to lose weight during pregnancy, check in with your doctor first. Many medical providers recommend that women do not try to deliberately lose weight during pregnancy because it could potentially interrupt the supply of nutrients to the growing fetus. However, a doctor can help you safely lose weight during pregnancy if you are in a situation in which that is necessary.
How much weight should a baby gain each month?
According to the Mayo Clinic, a baby should gain about 5 to 7 ounces each week during the first six months of life, and 3 to 5 ounces per week during from six to 12 months. This means they should gain about 1.25 to 1.75 pounds per month during their first six months of life, and 1 to 1.25 pounds per month during the next six-month period. By the end of their first year, they will likely have tripled their birth weight.
Why am I gaining weight so quickly during pregnancy?
During pregnancy, your body changes at a remarkable pace. Your baby is just one part of the growth spurt. Your uterus, placenta, breasts, fat tissues, and even your blood itself are all growing to nurture your developing child. This can feel rapid, especially toward the second half of your pregnancy, but it is expected. However, if you have concerns that the weight gain is happening too quickly, contact your doctor. You may need a lab test to rule out a serious medical condition.
Do prenatal vitamins make you gain weight?
No, prenatal vitamins do not make you gain weight, according to the CDC. Prenatal vitamins do not have a significant number of calories. Instead, prenatal vitamins contain nutrients such as folate, iron, and omega-3 fatty acids to help support your growing baby.