pregnant person on scale unsure how much weight to gain during pregnancyShare on Pinterest
Illustration by Alyssa Kiefer

Congratulations, you’re pregnant!

You’re now experiencing firsthand that your body is capable of miraculous feats including increasing its blood volume by almost 50 percent — part of that weight gain we’re talking about. As you grow this new budding life, your body also blossoms.

The extra pregnancy pounds help to nurture your new little one and keep you healthy during this busy time for your body. You’re eating for yourself and your baby now, so it’s important to choose a balanced daily diet.

Here’s how to know how much weight you should gain during pregnancy.

A healthy weight gain during pregnancy is different for every pregnant person. There is no magic number of how many pounds you should gain.

That said, too little weight or too much weight is not healthy for you or your baby. How much weight you gain during your pregnancy affects your health after your pregnancy. It can also affect your baby’s health right into their adult years.

How much weight you should gain while you’re pregnant depends on how much you weighed just before you got pregnant. Your body mass index (BMI) measures body fat based on your weight and height.

Your doctor or midwife may record your BMI at your first prenatal check-up. You can also use an online BMI calculator, like this one from the Centers for Disease Control (CDC) to get your estimated BMI.

To calculate your BMI, you’ll need to check your weight on a scale and use a measuring tape to measure around your waist.

A side note: A high BMI doesn’t necessarily mean you’re not healthy. And a low BMI doesn’t always mean you have a lower chance of health risks. For example, if you’re muscular you might have a higher BMI, but still be healthier than someone with a lower BMI. Other factors, like how much you exercise also make a difference.

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Once you know your rough BMI, you can calculate how much weight you should gain overall in your pregnancy with this handy chart from the CDC:

Weight / BMI before pregnancy Suggested weight gain for one baby Suggested weight gain for twin pregnancy
Underweight / less than 18.5 28 to 40 pounds 50 to 62 pounds
Average weight / 18.5 to 24.9 25 to 35 pounds 37 to 54 pounds
Overweight / 25 to 29.9 15 to 25 pounds 31 to 50 pounds
Obese / equal or greater to 30 11 to 20 pounds 25 to 42 pounds

Keeping track of your weight gain and eating a healthy balanced diet is just as important when you’re pregnant as when you are not.

Only about one-third of pregnant women put on the recommended range of pounds. Research from 2017 shows almost half of women gain too much weight and about 20 percent of women don’t put on enough weight during pregnancy.

Too much weight gain during pregnancy may contribute to:

  • gestational diabetes — a temporary condition specific to pregnant people
  • baby born large (more than 8 pounds, 13 ounces)
  • baby born prematurely (less than 37 weeks of pregnancy)
  • delivery complications like needing a cesarean delivery
  • too much bleeding during delivery
  • difficulty losing weight after pregnancy

Too much weight gain may also contribute to a higher risk of:

  • your baby being overweight or having obesity during childhood
  • your baby having a breathing problem
  • you or your baby developing type 2 diabetes later in life
  • you developing high blood pressure during or after your pregnancy

Too little weight gain during pregnancy can contribute to your developing gestational diabetes. In addition, your baby may:

  • have a low birth weight (less than 5 pounds, 8 ounces)
  • be born prematurely (less than 37 weeks gestation)
  • have difficulty eating and gaining weight
  • have a harder time fighting off infections
  • have long-term health and learning problems

Too little weight gain can also contribute to a higher risk of baby developing:

  • jaundice after birth
  • diabetes, heart disease, or other health conditions later on in life

Most women need to put on 25 to 35 pounds during their pregnancy. Pace yourself — you’re not really “eating for two,” and you don’t need to eat any more than normal until your second trimester.

You’re eating for one pregnant person, and this means eating more healthy whole foods (fruits, vegetables, lean meats) and cutting out the processed foods and excessive sweets. At most, you need to eat about 300 extra calories every day.

On top of your normal balanced daily diet, 300 calories might look like (choose one from the list!):

  • an apple with 2 tablespoons of peanut butter
  • whole wheat pita and a 1/4 cup of hummus
  • container of low-fat yogurt and a handful of blueberries

Your pregnancy weight gain is not going to be even all the way through. You may even lose some weight during the first trimester. Some women drop a few pounds because of serious morning sickness in the first few weeks of pregnancy.

Don’t worry. The nausea and vomiting usually go away as your pregnancy hums along into the fourth month.

Any weight loss usually isn’t enough to harm you or your baby, but talk to your doctor or midwife if you have severe morning sickness that is interfering with your life, as some treatment options are available.

On the flip side, it’s also important not to gain weight too quickly. When you gain your pregnancy weight matters just as much as how much you gain. Getting heavier too quickly early in your pregnancy can also lead to complications like gestational diabetes.

A rule of thumb is most of your weight gain should be in the second and third trimesters of pregnancy. But if you’re carrying twins or multiples you can break this rule! You will and should gain weight faster if you’re carrying more than one bun in the oven.

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Your weight between pregnancies also matters. A 2017 study found that women who maintained their pre-pregnancy BMI after their first child were less likely to get gestational diabetes when they were on their second pregnancy.

Also, don’t worry if the scale is all over the place during your pregnancy. You won’t gain the same amount of weight every week. Every person is different. You might gain more weight during some weeks and then level off before gaining a bit more.

Most of your weight gain will be in the third trimester, as your baby gets ready to be newborn size. You may gain up to a pound each week. Talk to your doctor or midwife if you’re worried about your weight gain during pregnancy.

You can see some pregnancy weight gain in your blooming belly, but where else are you carrying the new pounds?

If you gain the average amount of about 30 pounds during pregnancy, here’s what’s adding up to the new numbers on the scale (on average, approximately):

  • 7 1/2 pounds: your sweet babe!
  • 7 pounds: fat and protein
  • 4 pounds: blood
  • 4 pounds: body fluids — this explains the bloating!
  • 2 pounds: breasts
  • 2 pounds: amniotic fluid, the watery shock absorber protection for your baby
  • 1 1/2 pounds: placenta, the tree of blood vessels that gives your baby food and oxygen in the womb

If you’re part of the 20 percent of women who are not gaining enough pregnancy weight, you can add pounds with healthy, yet nutrient-dense foods. This means eating more foods that are high in healthy fats and proteins, like:

  • whole milk banana shake
  • coconut milk smoothie
  • peanut butter with fruit
  • nuts
  • nut butters
  • whole wheat tortilla chips with guacamole and sour cream
  • full fat Greek yogurt with granola and berries
  • grilled chicken wrap with whole wheat pita

Eating smaller meals more frequently may also help you gain weight. Don’t let too much time pass between meals. This is the one time when lots of snacking and “grazing” food is encouraged!

If you think you may be exercising too much or on your feet for work all day, talk to your doctor or midwife about how to best handle this precious time in your life.

A more common problem is gaining too much weight or gaining it too fast. If you know you can’t keep up the pace you’re at, here are ways to slow down the weight gain:

  • Keep a food journal to uncover any hidden sources of calories.
  • Avoid all processed and boxed foods.
  • Avoid juices, sodas, and sugary-prepared drinks.
  • Avoid packaged and high-carb snacks.
  • Avoid eating simple carbs like white bread, white rice, and white flour foods.
  • Avoid salty foods that might be adding to bloat and water weight.
  • Limit eating out and takeout dinners.
  • Get plenty of exercise every day.

Gaining weight too quickly can lead to edema (swelling in your body) and serious health risks like high blood pressure.

Let your doctor or midwife know if you feel like you’re gaining weight too quickly. Ask for advice on creating a healthy, balanced diet and exercise plan for your pregnancy.

Weight gain is necessary for a healthy pregnancy and a healthy baby. It’s also vital for your own health. How much weight you need to gain and when you gain it depends on you — every pregnant person is different.

That said, gaining too much or too little weight during your pregnancy can be harmful to your health and to your baby. It can even affect your health later on and your child’s health as an adult.

Talk to your doctor, midwife or nutritionist about the best diet and exercise plan for your pregnancy.