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Weight Gain During Pregnancy

Image for eating while pregnant article Finding out you are pregnant can be an exciting time. There are lots of things you may think about when you start planning ahead. It can also stir up some concerns. One of them may be the amount of weight you gain while you are pregnant. Pregnant women need to manage a proper diet and appropriate weight gain for a healthy pregancy and the nourishment of a growing baby.

Gaining weight during pregnancy can be tricky. If you gain too little or too much, it can harm your unborn baby and create complications for both of you.

You and your doctor can work out the details, but here is a general idea of what you need to know.

Optimal Weight Gain

The amount of weight you should gain during pregnancy depends upon several factors including your prepregnancy weight and your age. If you are of average weight for your height, you are encouraged to gain between 25-35 pounds. If you are underweight or have a low body mass index (BMI), you will need to gain a bit more. If you are overweight, you will be encouraged to gain a little less weight than average.

Women who are pregnant with twins or multiples will usually gain more weight than average.

A slow and steady weight gain over the 9 month period is best, but keep in mind that women gain weight at different rates. You should never try to lose weight during pregnancy, even if you are overweight. The burning of fat stores during pregnancy could cause your body to release substances that could harm your baby. Your doctor will suggest a weight range than best suits you, but the table below shows some general guidelines from the Institute of Medicine:

Pregnancy Status 1st Trimester
Weight Gain
2nd and 3rd Trimester
Weight Gain
Total Weight Gain
Underweight1-4 lbs.1-1.3 lbs/week28-40 lbs.
Normal Weight1-4 lbs.0.8-1 lbs/week25-35 lbs.
Overweight1-4 lbs.0.5-0.7 lbs/week15-25 lbs.
Obese1-4 lbs.0.4-0.6 lbs./week11-20 lbs.

Mothers carrying multiples (like twins) usually gain 33-48 lbs.

Fear of Fat

Many women fear the inevitable weight gain of pregnancy, even though it is normal and healthy. The important thing to keep in mind is that, for the majority of women, most of the weight gained is not fat. The following table illustrates how an average weight gain is distributed in pregnancy:

Approximate Distribution of Weight Gain in Average Pregnancy

Baby7.5 lbs
Uterus2.0 lbs
Placenta1.5 lbs
Blood volume increase in mother3-4 lbs
Amniotic fluid2 lbs
Fluids in mother's tissues3-4 lbs
Breast tissue increase1-3 lbs
Increased fat stores in mother6-8 lbs
Total Average 26-32 lbs

If your weight gain is too much, there are steps you can take to maximize nutrition and minimize fat intake.

Balancing Weight Gain

Both the amount and type of foods you eat during pregnancy will affect your weight gain.

During certain times in your pregnancy you will need to increase the number of calories that you take in. Talk to your doctor about how many calories you should add, it will vary per person and throughout your pregnancy. Early stages of pregnancy may not require extra calories, but your body may need more calories as your baby grows. But be careful, it can be easy to underestimate the calories you are adding. At least at first, count your calories to make sure you are only adding the recommended amount.

The types of food you eat are also important. Consider these guidelines when choosing your food:

Staying active will also help you manage a healthy weight. Talk to your doctor about any exercise precautions.

The most important thing to keep in mind is that you are growing a baby, who needs the extra calories to grow. Recommended weight gain is normal, and in fact, a sign of a healthy pregnancy. Tracking your calories, eating nutritious foods, and staying active will help you keep your weight gain within guidelines. It is the best thing you can do for you and your unborn baby.

Losing Weight after You Have Your Baby

Your postpartum weight will, in part, be affected by how much weight you gained during pregnancy. If you gain too much weight during pregnancy or develop poor eating habits and a sedentary lifestyle, you may have more difficulty losing the weight after the baby is born. The following factors help women to lose weight more quickly after giving birth:

  • Eat a healthful, well-balanced diet that is low in fat, high in fiber, and rich in nutrients
  • Breastfeed—your body will burn more calories while breastfeeding
  • Exercise—aim for 30 minutes (regular aerobic exercises that involve the large muscles and elevate the heart rate are best for burning calories) per day most days of the week

It will take some time to lose weight after pregnancy. Instead of focusing on weight loss alone work on developing or maintaining healthy habits like good nutrition and regular physical activity. This will keep you healthy and help you manage some of the sleepless nights you have ahead.


ChooseMyPlate—US Department of Agriculture

The American Congress of Obstetricians and Gynecologists


The Society of Obstetricians and Gynaecologists of Canada

Womens Health Matters


Impact of physical activity during pregnancy and postpartum on chronic disease risk. Med Sci Sports Exerc. 2006;38(5):989-1006.

Nutrition in pregnancy. EBSCO DynaMed website. Available at: Updated Available at: Updated April 10, 2016. Accessed August 2, 2016.

Pregnancy weight gain. American Pregnancy Association website. Available at: Updated December 2015. Accessed August 2, 2016.

Weight gain in pregnancy. EBSCO DynaMed website. Available at: Updated July 8, 2015. Accessed August 2, 2016.

Last reviewed August 2016 by Michael Woods, MD  Last Updated: 8/2/2016