Your pregnant body

• Your body goes through major changes during pregnancy.
• Weight gain, breast changes and aches and pains are common.
• There are ways to deal with common discomforts and changes.

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When you’re pregnant, you get to eat as many donuts and French fries as you want, right? Wrong! You only need about 300 extra calories a day during pregnancy to support your baby’s growth and development. So you don’t need to be chowing down everything in sight!

Be careful about the amount of weight you gain during your pregnancy. Gaining too much or too little weight can be harmful to you and your baby.

Is gaining the right amount of weight important during pregnancy?
You bet. It's important to gain the right amount of weight for your body. Doing so can help protect the health of your baby. Compared to women who gain a healthy amount of weight during pregnancy:

• Women who gain too little are more likely to have a baby with low birthweight (less than 5 pounds, 8 ounces)
• Women who gain too much are more likely to have a large baby or a premature baby. A premature baby is born too early, before 37 completed weeks of pregnancy. Theses moms also may also have health conditions, like diabetes and high blood pressure. These conditions can cause problems during pregnancy.

How much weight should you gain during pregnancy?
It depends on your body mass index (BMI) before you get pregnant. BMI is a measure of body fat based on your height and weight.

Your health care provider uses your pre-pregnancy BMI to figure out how much weight you need to gain during pregnancy. It usually works out like this:

If you’re pregnant with one baby: 

• If you were at a healthy weight before pregnancy, you want to gain about 25 to 35 pounds during pregnancy. You gain 1 to 4½ pounds in the first trimester and then about one pound a week in the second and third trimesters. 
• If you were underweight before pregnancy, you want to gain about 28 to 40 pounds during pregnancy. You gain 1 to 4½ pounds in the first trimester and then a little more than a pound a week in the second and third trimesters. 
• If you were overweight before pregnancy, you want to gain about 15 to 25 pounds during pregnancy. You gain 1 to 4½ pounds in the first trimester and then a little more than a ½ pound every week in the second and third trimesters.
• If you were obese before pregnancy, you want to gain about 11 to 20 pounds during pregnancy. You gain 1 to 4½ pounds in the first trimester and then a little less than a ½ pound every week in the second and third trimesters.

If you’re pregnant with twins: 

• If you were at a healthy weight before pregnancy, you want to gain about 37 to 54 pounds during pregnancy. 
• If you were overweight before pregnancy, you want to gain about 31 to 50 pounds during pregnancy.
• If you were obese before pregnancy, you want to gain about 25 to 42 pounds during pregnancy.

Putting on weight slowly and steadily is best. Don't worry too much if you gain a little more or a little less than you think you should in any week. You may have a few growth spurts when you gain several pounds in a short time, and then level off. And while you don't want to gain too much weight, don’t ever try to lose weight during pregnancy.

If you’re worried about your weight gain, talk to your health care provider.

How can you track your weight gain during pregnancy?
Use our weight-gain tracking chart to follow your progress.

Last reviewed September 2009

See also: Tracking your weight gain, How your baby grows