Pregnancy weight gain: What's healthy?

From promoting your baby's development to paving the way for post-pregnancy weight loss, here's why pregnancy weight gain matters.

By Mayo Clinic Staff

Healthy lifestyle habits can help you manage pregnancy weight gain and support your baby's health. Also, making smart meal choices during pregnancy can make it easier to shed the extra pounds after you deliver your baby.

Pregnancy weight-gain guidelines

There's no one-size-fits-all approach to pregnancy weight gain. Appropriate weight gain during pregnancy depends on various factors, including your pre-pregnancy weight and body mass index (BMI). Your health and your baby's health also play a role. Work with your health care provider to determine what's right for you.

Consider these general guidelines for pregnancy weight gain:

Pre-pregnancy weight Recommended weight gain
Source: Institute of Medicine and National Research Council
Underweight (BMI below 18.5) 28 to 40 lbs. (about 13 to 18 kg)
Healthy weight (BMI 18.5 to 24.9) 25 to 35 lbs. (about 11 to 16 kg)
Overweight (BMI 25 to 29.9) 15 to 25 lbs. (about 7 to 11 kg)
Obese (BMI 30 or more) 11 to 20 lbs. (about 5 to 9 kg)

When you're carrying twins or other multiples

If you're carrying twins or other multiples, you'll likely need to gain more weight. Again, work with your health care provider to determine what's right for you.

Consider these general guidelines for pregnancy weight gain if you're carrying twins:

Pre-pregnancy weight Recommended weight gain
Source: Institute of Medicine and National Research Council
Underweight (BMI below 18.5) 50 to 62 lbs. (about 23 to 28 kg)
Healthy weight (BMI 18.5 to 24.9) 37 to 54 lbs. (about 17 to 25 kg)
Overweight (BMI 25 to 29.9) 31 to 50 lbs. (about 14 to 23 kg)
Obese (BMI 30 or more) 25 to 42 lbs. (about 11 to 19 kg)

When you're overweight

Being overweight before pregnancy increases the risk of various pregnancy complications, such as gestational diabetes, high blood pressure disorders of pregnancy — including preeclampsia — the need for a C-section and premature birth.

Although a certain amount of pregnancy weight gain is recommended for people who are overweight or obese before pregnancy, some research suggests that people who are obese can safely gain less weight than the guidelines recommend. More research is needed.

Work with your health care provider to determine how much weight you should gain during pregnancy. Your health care provider can offer guidance on nutrition and physical activity and strategies to manage your weight throughout pregnancy.

When you're underweight

If you're underweight before pregnancy, it's essential to gain a reasonable amount of weight while you're pregnant. Without the extra weight, your baby might be born early (premature birth) or smaller than expected.

When you gain too much

Gaining too much weight during pregnancy can increase your baby's risk of health problems, such as being born significantly larger than average, and complications at birth, such as the baby's shoulder becoming stuck after the head is delivered (shoulder dystocia). Excessive weight gain during pregnancy can also increase your risk of postpartum weight retention.

Where does pregnancy weight gain go?

Let's say your baby weighs in at 7 or 8 pounds (about 3 to 3.6 kilograms). That accounts for some of your pregnancy weight gain. What about the rest? Here's a sample breakdown:

  • Larger breasts: 1 to 3 pounds (about 0.5 to 1.4 kilogram)
  • Larger uterus: 2 pounds (about 0.9 kilogram)
  • Placenta: 1 1/2 pounds (about 0.7 kilogram)
  • Amniotic fluid: 2 pounds (about 0.9 kilogram)
  • Increased blood volume: 3 to 4 pounds (about 1.4 to 1.8 kilograms)
  • Increased fluid volume: 2 to 3 pounds (about 0.9 to 1.4 kilograms)
  • Fat stores: 6 to 8 pounds (about 2.7 to 3.6 kilograms)

Putting on the pounds

In the first trimester, most people don't need to gain much weight. This is good news if you're struggling with morning sickness.

If you start out at a healthy weight, you need to gain only about 1 to 4 pounds (0.5 to 1.8 kilograms) in the first few months of pregnancy. You can do this by eating a healthy diet — no extra calories are necessary.

Steady weight gain is more important in the second and third trimesters — especially if you start out at a healthy weight or you're underweight. According to the guidelines, you'll gain about 1 pound (0.5 kilogram) a week until delivery. An extra 300 calories a day — half a sandwich and a glass of skim milk — might be enough to help you meet this goal. For people who are overweight or obese, the guidelines translate to a weight gain of about 1/2 pound (0.2 kilogram) a week in the second and third trimesters. Try adding a glass of low-fat milk or an ounce of cheese and a serving of fresh fruit to your diet.

Working with your health care provider

Your health care provider will keep a close eye on your weight. You can do your part by eating a healthy diet. Also, for most pregnant women, getting at least 30 minutes of moderate-intensity exercise, such as brisk walking or swimming, is recommended on most days. However, talk to your health care provider before starting an exercise program. And be sure to keep your prenatal appointments. To keep your pregnancy weight gain on target, your health care provider might offer suggestions for boosting calories or scaling back as needed.

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Feb. 09, 2022 See more In-depth